Cross-layer cooperative control and optimal scheduling method and system of water-light-storage complementary system

Abstract

The application provides a kind of translayer coordination control and optimization scheduling method and system of water-light-storage complementary system, belongs to water-light-storage complementary system control and scheduling technical field, the method includes: collecting the operating state quantity of the common connection point of water-light-storage complementary system;Based on day-ahead scheduling plan, daily correction result, real-time operating state and preset unified state machine, generate the translayer control parameter set corresponding to each operating state respectively;Determine the current operating state, and obtain the translayer control parameter set of the current operating state;On the basis of the translayer control parameter set of the current operating state, arbitrate dynamic support increment, determine the energy storage output instruction;According to the energy storage output instruction, perform and off-grid switching control;When off-grid switching is completed, gradually exit the dynamic support increment according to the preset regression slope.The application realizes the translayer coordination of upper economic dispatching and lower dynamic control of water-light-storage complementary system, and improves the dynamic executability under disturbance and state switching scenarios.

Description

Technical Field

[0001] This invention relates to the field of control and scheduling technology for hydro-solar-storage complementary systems, and in particular to a cross-layer collaborative control and optimized scheduling method and system for hydro-solar-storage complementary systems. Background Technology

[0002] With the continuous increase in the penetration rate of renewable energy, hydropower-solar-storage complementary systems, which combine hydropower, photovoltaics, and energy storage, have become an important technological form of new power systems due to their significant advantages in smoothing power fluctuations, improving the absorption capacity of renewable energy, and enhancing the reliability of local power grid supply. Domestic and international scholars and engineers have conducted relatively systematic research on the operation control and optimized scheduling of such systems from multiple levels, including planning and scheduling, stability control, inverter strategies, and grid connection switching.

[0003] In existing research, the planning and scheduling layer typically only outputs day-ahead or medium-to-long-term power plans, and its scheduling schemes often lack executability under sudden disturbances or grid connection / disconnection switching scenarios. Meanwhile, the underlying control strategies—including VSG adaptive parameter tuning, mode switching logic, and seamless grid connection / disconnection switching technology—mostly rely on local electrical quantities for passive response, lacking a coordination mechanism with the upper-level scheduling plan. Furthermore, existing VSG control is limited to inverter-level parameter adjustment, lacking a cross-timescale coordination mechanism for fast energy storage response and slow hydropower replacement; while grid connection / disconnection switching schemes focus on the continuity of the converter's own state, without considering the global backup coordination of multiple heterogeneous power sources. As for some scheduling methods involving system state assessment, their risk preference mechanisms only apply to the setting of uncertainty boundaries and do not extend to the execution level, such as dynamically supporting incremental allocation, mode switching preparation, and multi-timescale succession control.

[0004] It is evident that existing technologies generally suffer from the common defect of disconnect between upper-level economic scheduling and lower-level dynamic control. The scheduling results are difficult to dynamically execute in the entire process of disturbance and handover. The system cannot reliably guarantee the safety and stability of weak network support, pre-islanding preparation and off-network operation while taking into account economic efficiency.

[0005] Therefore, there is an urgent need to propose a cross-layer collaborative control and optimization scheduling method for hydro-solar-storage complementary systems, so that the economic scheduling results have dynamic executability under disturbance and mode switching scenarios. Summary of the Invention

[0006] This invention provides a cross-layer collaborative control and optimization scheduling method and system for a hydro-solar-storage complementary system, which solves the defect of disconnect between upper-layer economic scheduling and lower-layer dynamic control in the prior art, and realizes cross-layer collaborative control of the hydro-solar-storage complementary system.

[0007] In a first aspect, the present invention provides a cross-layer collaborative control and optimized scheduling method for a hydro-solar-storage complementary system, comprising: Collect operational status data of the common connection point of the hydro-solar-storage complementary system; Based on the day-ahead scheduling plan, intraday correction results, real-time operating status, and preset unified state machine of the aforementioned hydro-solar-storage complementary system, a cross-layer control parameter set corresponding to each operating status is generated; wherein, the cross-layer control parameter set includes the baseline power plan of energy storage, hydropower, and photovoltaic, as well as control boundary parameters used to ensure the executability of dynamic support and state switching. The current operating state of the unified state machine is determined based on the operating state variables of the common connection point, and the cross-layer control parameter set of the current operating state is obtained. Based on the cross-layer control parameter set of the current operating state, the dynamic support increment is arbitrated to determine the energy storage output command; Execute and switch off-grid according to the energy storage output command; Once the on-grid / off-grid switching is complete, the dynamic support increment will be gradually withdrawn according to the preset regression slope.

[0008] According to the present invention, a cross-layer collaborative control and optimized scheduling method for a hydro-solar-storage complementary system is provided, wherein the unified state machine includes a grid-connected operation state, a weak grid support state, a pre-islanding state, an off-grid operation state, a reconnection preparation state, and a reconnection execution state. The switching method between the various operating states of the unified state machine is as follows: When any one of the frequency deviation, frequency change rate, or voltage deviation of the common connection point exceeds the first preset threshold, is less than the second preset threshold, and the duration exceeds the first preset time, the grid-connected operation state is switched to the weak grid support state. When any one of the frequency deviation, frequency change rate, or voltage deviation of the common connection point exceeds the second preset threshold, or when a disconnection command signal is received, the system switches from the weak network support state to the pre-islanding state. Once the grid connection switch is confirmed to be disconnected, the system transitions from pre-islanded state to off-grid operation state. When the frequency deviation, frequency change rate, or voltage deviation of the common connection point all recover to within the first preset threshold and the duration exceeds the second preset time, the system returns from the weak network support state to the grid-connected operation state. When the upper-level power grid is detected to have recovered and the conditions for reconnection to the grid are met, the system will switch from off-grid operation to reconnection preparation state. When the voltage, frequency, and phase angle synchronization errors of the local side and the grid side all meet the preset synchronization threshold, the system transitions from the reconnection preparation state to the reconnection execution state.

[0009] According to the present invention, a cross-layer collaborative control and optimized scheduling method for a hydro-solar-storage complementary system is provided. The method generates a set of cross-layer control parameters corresponding to each operating state based on the day-ahead scheduling plan, intraday correction results, real-time operating status, and a preset unified state machine of the hydro-solar-storage complementary system. The method includes: Based on factors including the day-ahead dispatch plan, intraday correction results, load forecast, photovoltaic forecast, hydropower available output, energy storage SOC, equipment capacity constraints, operating costs, and supply guarantee requirements, the energy storage baseline power, hydropower baseline power, and photovoltaic baseline power are generated respectively. Based on the energy storage baseline power, hydropower baseline power, and photovoltaic baseline power, and combined with the real-time operating status and the preset unified state machine, control boundary parameters for lower-level control are further generated; the control boundary parameters include at least: upper limit of energy storage inertia support, upper limit of energy storage droop support, upper limit of energy storage recovery power, minimum state of charge threshold for switching preparation, hydropower reserve release slope, reserved power for photovoltaic auxiliary support, and reconnection synchronization threshold.

[0010] According to the present invention, a cross-layer collaborative control and optimized scheduling method for a hydro-solar-storage complementary system is provided. The upper limit of energy storage inertia support, the upper limit of energy storage droop support increment, and the upper limit of energy storage recovery power are determined based on allocation coefficients related to the current operating state and the available rapid support power of energy storage, respectively. The allocation coefficients related to the current operating state are determined based on frequency deviation, continuous power deficit, hydropower succession progress, or photovoltaic auxiliary support margin. The minimum state of charge threshold for switching preparation is obtained by superimposing the energy storage safety lower limit, the energy required for future islanded power supply, the rapid support energy at the moment of switching, and the safety margin. The hydropower reserve release slope is jointly determined by the physical ramping capability of the hydropower unit and the currently adjustable capacity. The reserved power for photovoltaic auxiliary support is determined by the current available maximum output of photovoltaic power, the photovoltaic baseline output, and the allowable load reduction margin. The reconnection synchronization threshold is pre-set according to the synchronization requirements of the grid-connected switch, protection devices, and the power grid.

[0011] According to the present invention, a cross-layer collaborative control and optimized scheduling method for a hydro-solar-storage complementary system is provided, wherein the step of arbitrating dynamic support increments based on the cross-layer control parameter set of the current operating state to determine the energy storage output command includes: Based on the operating status parameters of the common connection point, the frequency deviation, frequency change rate, and DC bus voltage deviation of the hydro-solar-storage complementary system are determined, and the dynamic support increment is calculated; wherein, the dynamic support increment includes the inertia support increment, the droop support increment, and the DC bus voltage compensation increment. When the dynamic support increment is consistent with the energy storage baseline power direction in the cross-layer control parameter set of the current operating state, the baseline power is superimposed on the dynamic support increment within the range of available rapid support power for energy storage to obtain an energy storage output command. When the dynamic support increment is opposite to the energy storage baseline power direction in the cross-layer control parameter set of the current operating state and there is a directional conflict, arbitration is carried out according to the current operating state and a preset arbitration rule to determine the energy storage output command. The energy storage output command is constrained by the control boundary parameters in the cross-layer control parameter set.

[0012] According to the present invention, a cross-layer collaborative control and optimized scheduling method for a hydro-solar-storage complementary system is provided, wherein the step of executing off-grid switching control according to the energy storage output command includes: When the hydro-solar-storage complementary system enters a weak grid support state, a pre-island state, or an off-grid operation state, it undertakes frequency support according to the energy storage output command, and the hydro-generator unit gradually increases its output according to the pre-generated reserve release slope to take over the continuous power shortage from the energy storage. When the current maximum available output of photovoltaic power is greater than the photovoltaic baseline power, the difference between the current maximum available output and the photovoltaic baseline power is used as the photovoltaic auxiliary support reserved power. When the frequency of the hydro-photovoltaic-storage complementary system is lower than the reference value or there is an active power deficit, the photovoltaic output is increased within the range of the photovoltaic auxiliary support reserved power.

[0013] According to the present invention, a cross-layer collaborative control and optimal scheduling method for a hydro-solar-storage complementary system is provided, the method further comprising: A two-layer optimization scheduling model is established, which considers operating costs, curtailment costs, energy storage attenuation costs, and switching feasibility constraints. The two-layer optimization model includes an upper-layer optimization model and a lower-layer rolling optimization model. The upper-level optimization model is used to optimize the baseline power plan and reserve configuration for the day or day. The upper-level optimization model takes the minimum hydropower operation cost or hydropower regulation cost, the minimum curtailment of solar power, the minimum energy storage attenuation cost, and the minimum risk of non-executability of state switching as the optimization objectives. The lower-level rolling optimization model is used to correct the cross-layer control parameter set according to the real-time status and limit the impact of the dynamic support increment on the energy storage lifetime and the feasibility of subsequent state switching. The lower-level rolling optimization model takes the minimum frequency deviation, the minimum frequency change rate, the minimum DC surface voltage deviation, the minimum deviation between the energy storage output command and the energy storage baseline power, and the minimum risk of real-time state switching not being executable as optimization objectives. The upper-level optimization model and the lower-level rolling optimization model together satisfy the following constraints: power balance constraint, equipment capacity constraint, energy storage SOC constraint, hydropower ramping constraint, photovoltaic available output constraint, minimum SOC constraint for switching preparation, energy storage available rapid support power constraint, and grid reconnection synchronization threshold constraint.

[0014] Secondly, the present invention also provides a cross-layer collaborative control and optimization scheduling system for a hydro-solar-storage complementary system, comprising: The energy management layer is used to generate cross-layer control parameter sets corresponding to each operating state based on the day-ahead scheduling plan, intraday correction results, real-time operating status, and preset unified state machine of the hydro-solar-storage complementary system. The cross-layer control parameter sets include the baseline power plans for energy storage, hydropower, and photovoltaics, as well as control boundary parameters to ensure the executability of dynamic support and state switching. The coordination control layer is used to collect the operational status data of the common connection point of the hydro-solar-storage complementary system; determine the current operating state of the unified state machine based on the operational status data of the common connection point, and obtain the cross-layer control parameter set of the current operating state from the energy management layer; arbitrate the dynamic support increment based on the cross-layer control parameter set of the current operating state to determine the energy storage output command; execute the grid connection / off-grid switching control according to the energy storage output command; and after the grid connection / off-grid switching is completed, gradually withdraw the dynamic support increment according to the preset regression slope. The physical device layer is used to execute the speed regulation and excitation control of the hydropower unit of the hydropower control unit, the photovoltaic inverter control of the photovoltaic control unit, the energy storage converter control of the energy storage control unit, and the energy storage battery management according to the instructions of the coordination control layer.

[0015] Thirdly, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, it implements the cross-layer collaborative control and optimized scheduling method for the hydro-solar-storage complementary system as described above.

[0016] Fourthly, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the cross-layer collaborative control and optimized scheduling method for the hydro-solar-storage complementary system as described above.

[0017] Fifthly, the present invention also provides a computer program product, including a computer program, which, when executed by a processor, implements the cross-layer collaborative control and optimized scheduling method for the hydro-solar-storage complementary system as described above.

[0018] The beneficial effects of the technical solutions provided by some embodiments of the present invention include at least the following: 1) The present invention provides a cross-layer collaborative control and optimization scheduling method and system for a hydro-solar-storage complementary system. By transforming the executability of switching into a set of cross-layer control parameters that can be generated and called, a direct mapping mechanism from the upper-layer optimization results to the lower-layer fast control boundary is established, avoiding the problem in the traditional scheme that the scheduling results only form a power plan and cannot guarantee dynamic executability. 2) This invention improves the continuity of mode switching and the integrity of control logic by covering the entire process of grid connection, weak grid connection, pre-islanding, off-grid connection and reconnection of the water-solar-storage complementary system through a unified state machine; 3) This invention achieves coordination between economic scheduling, frequency support, and handover preparation through a mode-dependent arbitration structure of baseline power planning and dynamic support increment, thereby reducing control conflicts between upper and lower layers. 4) This invention improves the adaptability of scheduling results to disturbance and state switching scenarios by incorporating energy storage state of charge preparation, hydropower reserve release capacity, photovoltaic auxiliary support margin and synchronization threshold into the optimization scheduling process. 5) This invention, through a synergistic mechanism of fast energy storage adjustment, slow hydropower replacement, and conditional photovoltaic support, ensures frequency and voltage stability while reducing the lifespan loss caused by long-term, high-intensity operation of energy storage. 6) This invention enables the system to smoothly return from the rapid support state to the optimized operating point through the succession completion judgment and regression mechanism after the disturbance ends, avoiding economic losses and subsequent reduction in switching capability caused by the long-term stagnation of support power. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the cross-layer collaborative control and optimization scheduling system for the hydro-solar-storage complementary system provided by the present invention; Figure 2 This is one of the flowcharts illustrating the cross-layer collaborative control and optimized scheduling method for the hydro-solar-storage complementary system provided by the present invention; Figure 3 This is a schematic diagram of the unified state machine and its state transition provided by the present invention; Figure 4 This is a schematic diagram of the process for generating and calling cross-layer control parameter sets provided by the present invention; Figure 5 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0022] The existing operation control and optimization scheduling of hydro-solar-storage complementary systems have the following shortcomings: At the planning and scheduling level, existing schemes have proposed cascade hydropower-solar-storage complementary allocation and scheduling models based on the analytical expression of reservoir power generation potential energy. By transforming the traditional high-dimensional nonlinear programming problem into an algebraic solution problem, computational efficiency and stability are effectively improved. These methods focus on medium- to long-term or day-ahead scales of power balance and water level control, and can output reasonable power plans. However, their scheduling results usually only remain at the power command level, failing to further map the plan to the dynamic support boundaries available for lower-level rapid control—such as the upper limit of inertia support provided by energy storage, the safe state of charge (SOC) threshold required for switching preparation, and the release slope constraints of hydropower reserve capacity. This deficiency makes it difficult to guarantee the actual executability of the scheduling scheme when facing sudden disturbances or grid connection / disconnection switching.

[0023] In the field of microgrid stability control, existing research has introduced reinforcement learning and virtual synchronous generator (VSG) technology. This involves real-time adjustment of virtual inertia and damping parameters, and switching between VSG and energy balance modes based on current saturation and frequency change rate to suppress ultra-low frequency oscillations. While this method achieves mode self-adaptation, its switching decisions primarily rely on local electrical quantity information and do not incorporate economic indicators such as reserve configurations and energy storage reserves from the upper-level scheduling plan into the switching preparation process. This can lead to dynamic support response conflicts with the scheduling baseline power direction, and even excessive consumption of energy storage reserves before islanding operation, jeopardizing power supply security during subsequent off-grid phases.

[0024] Regarding VSG control itself, existing technologies have proposed a photovoltaic-storage coordinated control strategy based on frequency deviation and rate of change, dividing the frequency regulation stage and calculating inertia-damping parameters in real time, which effectively improves the frequency disturbance suppression effect. However, this strategy is still limited to inverter-level parameter adaptation and does not involve cross-timescale coordination among the three heterogeneous power sources: hydropower, photovoltaics, and energy storage. Especially in long-term disturbance scenarios, the lack of a coordination mechanism between the fast response of energy storage and the slow replacement of hydropower often leads to energy storage continuously bearing the main regulation task, accelerating its lifespan reduction.

[0025] Regarding seamless switching between grid-connected and off-grid systems, existing solutions have achieved output voltage continuity and islanded inertia support during switching of energy storage converters through mode prediction, unified state-space equations, and phase-locked loop-free pre-synchronization technology. However, the control object of this solution is limited to the converter itself, and the pre-synchronization and switching trigger conditions mainly rely on grid-side electrical quantities, failing to incorporate global system information such as the reserve release capacity of hydropower units, the reserved load reduction margin of photovoltaics, and the actual SOC state of energy storage as inputs for switching preparation. Therefore, this method is difficult to extend to hydro-photovoltaic-storage complementary systems that include multiple heterogeneous energy sources and have more adjustable resources after switching.

[0026] Furthermore, in the optimized scheduling of multi-energy complementary integrated energy stations, some studies have attempted to construct a composite index of system readiness through principal component analysis and map it to generate a dynamic risk preference coefficient to adjust the uncertainty radius of the scheduling model, thereby achieving a balance between economy and safety. However, the scope of this risk preference mechanism is still limited to setting the uncertainty boundary at the scheduling layer and has not extended to the underlying execution stage. It fails to provide operational guidance for dynamically supporting incremental allocation, setting preparatory thresholds for mode switching, and multi-timescale succession control.

[0027] In summary, existing technologies generally suffer from a common problem: a disconnect between "upper-level optimized scheduling" and "lower-level dynamic control." The economic scheduling layer only generates power plans but fails to translate them into control boundaries oriented towards mode switching and disturbance support. The lower-level control strategies rely on local electrical quantities for passive responses, lacking proactive adaptation to scheduling plans and switching preparation requirements. This layered and fragmented design makes it difficult for the scheduling results of hydro-solar-storage complementary systems to possess dynamic executability when facing disturbances, grid-connected to off-grid switching, and islanded operation. It fails to reliably guarantee the safety and robustness of weak grid support, pre-islanding preparation, and stable off-grid operation while pursuing economical operation goals.

[0028] Please see Figure 1 , Figure 1 A schematic diagram of a cross-layer collaborative control and optimization scheduling system for a hydro-solar-storage complementary system provided as an embodiment of the present invention is shown. The system includes: The energy management layer is used to generate cross-layer control parameter sets corresponding to each operating state based on the day-ahead scheduling plan, intraday correction results, real-time operating status, and preset unified state machine of the hydro-solar-storage complementary system. The cross-layer control parameter sets include the baseline power plans for energy storage, hydropower, and photovoltaics, as well as control boundary parameters to ensure dynamic support and the executability of state switching. The coordination control layer is used to collect the operational status data of the common connection point of the hydro-solar-storage complementary system; determine the current operating status of the unified state machine based on the operational status data of the common connection point, and obtain the cross-layer control parameter set of the current operating status from the energy management layer; arbitrate the dynamic support increment based on the cross-layer control parameter set of the current operating status to determine the energy storage output command; execute the grid connection / off-grid switching control according to the energy storage output command; after the grid connection / off-grid switching is completed, the dynamic support increment will be gradually withdrawn according to the preset regression slope. The physical equipment layer is used to execute the speed regulation and excitation control of the hydropower unit of the hydropower control unit, the photovoltaic inverter control of the photovoltaic control unit, the energy storage converter control of the energy storage control unit, and the energy storage battery management according to the instructions of the coordination control layer.

[0029] This invention establishes a hierarchical collaborative control architecture consisting of an energy management layer, a coordination control layer, and a physical equipment layer. The energy management layer generates a cross-layer control parameter set, including baseline power plans and control boundary parameters, and then distributes this set to the coordination control layer. The coordination control layer executes a unified state machine based on real-time operating status variables to determine the current operating state. Based on the cross-layer control parameter set corresponding to the current operating state, it performs baseline power and dynamic support incremental arbitration, grid connection / off-grid switching control, hydropower reserve release, and power regression. The physical equipment layer executes hydropower speed regulation and excitation control, photovoltaic inverter control, energy storage converter control, and energy storage battery management according to control commands from the coordination control layer. This hierarchical collaborative control architecture is centered on "parameterized switching executability," enabling dynamic executability of economic dispatch results under disturbance and mode switching scenarios, achieving a balance between safety, stability, and economy in hydro-photovoltaic-storage complementary systems.

[0030] like Figure 1 As shown, the physical equipment layer specifically includes hydropower units, photovoltaic units, energy storage units, local loads, a common AC bus, a point of common coupling (PCC), a grid-connected switch, and the external power grid. The hydropower unit includes hydroelectric generators and their speed regulation and excitation devices; the photovoltaic unit includes photovoltaic arrays and photovoltaic inverters; the energy storage unit includes an energy storage battery system, an energy storage battery management system, and an energy storage converter. The hydropower unit, photovoltaic unit, energy storage unit, and local load are all connected to the common AC bus, which is connected to the PCC via the grid-connected switch and then to the external power grid.

[0031] The cross-layer collaborative control and optimization scheduling system for a hydro-solar-storage complementary system described above and the cross-layer collaborative control and optimization scheduling method for a hydro-solar-storage complementary system described below can be referred to in correspondence.

[0032] The following describes a cross-layer collaborative control and optimization scheduling method for a water-solar-storage complementary system based on the above-mentioned cross-layer collaborative control and optimization scheduling system for a water-solar-storage complementary system.

[0033] Please see Figure 2 , Figure 2 One of the flowcharts for a cross-layer collaborative control and optimized scheduling method for a hydro-solar-storage complementary system provided as an embodiment of the present invention includes: S101. Collect the operational status data of the common connection point of the water-solar-storage complementary system; S102. Based on the day-ahead scheduling plan, intraday correction results, real-time operating status, and preset unified state machine of the hydro-solar-storage complementary system, generate cross-layer control parameter sets corresponding to each operating status; wherein, the cross-layer control parameter sets include the baseline power plans of energy storage, hydropower, and photovoltaic, as well as control boundary parameters used to ensure dynamic support and the executability of state switching. S103. Determine the current operating state of the unified state machine based on the operating state variables of the common connection point, and obtain the cross-layer control parameter set of the current operating state; S104. Based on the current cross-layer control parameter set, arbitrate the dynamic support increment to determine the energy storage output command; S105. Execute and switch off-grid according to the energy storage output command; S106. After the grid connection is completed, the dynamic support increment will be gradually withdrawn according to the preset regression slope.

[0034] This invention establishes a direct mapping mechanism from upper-level optimization results to lower-level fast control boundaries by transforming state switching executability into a set of cross-layer control parameters that can be generated and called. This avoids the problem in traditional schemes where scheduling results only form power plans and cannot guarantee dynamic executability. Furthermore, through a mode-dependent arbitration structure that combines baseline power plans with dynamic support increments, it achieves coordination between economic scheduling, frequency support, and switching preparation, thereby reducing control conflicts between upper and lower layers.

[0035] In the above implementation, step S101 mainly involves real-time acquisition of operational status data of the common connection point of the hydro-solar-storage complementary system through the coordination control layer.

[0036] Understandably, the point of common coupling (PCC) is the electrical connection boundary between the hydro-solar-storage complementary system and the external power grid, local load bus, or common AC bus. These PCCs are typically used to collect voltage, frequency, phase angle, and power flow information from the grid-connected or bus-connected side of the system, serving as the basis for weak network support, pre-islanding, off-grid operation, and reconnection judgments.

[0037] For example, in scenarios where a hydro-solar-storage complementary power station is integrated into the distribution network, the point of common coupling (PCC) can be the high-voltage busbar of the step-up transformer, the grid connection switch / circuit breaker, the 10kV or 35kV grid connection busbar, the transmission line access point, or the metering and protection point where the power station connects to the upper-level power grid. In microgrid or industrial park energy supply scenarios, the PCC can also be the connection point between the common AC busbar after the aggregation of hydropower, photovoltaic, energy storage, and local loads and the external power grid, i.e., the location on both sides of the grid connection switch used for synchronization detection and power flow monitoring.

[0038] Specifically, the system collects operational status data such as point of common coupling voltage, frequency, phase angle, line power flow, hydropower unit output, water level, head, available photovoltaic output, photovoltaic load margin, energy storage status of charge, available energy storage charging and discharging power, DC bus voltage, load power, grid connection switch status, disconnection signal, reconnection permission signal, and protection device information.

[0039] In the above implementation, step S102 mainly involves generating a set of cross-layer control parameters corresponding to each operating state of the hydro-solar-storage complementary system through the energy management layer.

[0040] Generally, hydro-solar-storage complementary systems encompass scenarios such as grid-connected operation, weak grid support, pre-islanding, off-grid operation, reconnection preparation, and reconnection execution. These scenarios are switched between during operation. Different scenarios correspond to different control requirements. For example, grid-connected operation primarily focuses on economic dispatch and reserve maintenance; weak grid support primarily focuses on dynamic frequency and voltage support; pre-islanding primarily focuses on energy storage SOC reservation, grid controller hot standby, and pre-release of hydropower reserves; off-grid operation primarily focuses on independent power supply to local loads and hydropower replacement of energy storage; and reconnection preparation and reconnection execution primarily focus on voltage, frequency, and phase angle synchronization between the local side and the grid side, as well as the smooth handover of control after the grid connection switch is closed.

[0041] Based on these scenarios, this invention constructs a unified state machine to manage state transitions, thereby determining the cross-layer control parameter set corresponding to each operating state. For example... Figure 3 The diagram shown is a schematic of the unified state machine and its state transitions according to the present invention.

[0042] In some possible implementations, such as Figure 3 As shown, the unified state machine includes grid-connected operation state, weak network support state, pre-islanding state, off-grid operation state, reconnection preparation state, and reconnection execution state; The transition between the various operating states of the unified state machine is as follows: When any one of the frequency deviation, frequency change rate, or voltage deviation at the common connection point exceeds the first preset threshold, is less than the second preset threshold, and lasts for more than the first preset time, the system switches from grid-connected operation to weak grid support. When any of the frequency deviation, frequency change rate, or voltage deviation of the common connection point exceeds the second preset threshold, or when a disconnection command signal is received, the system switches from the weak network support state to the pre-islanding state. Once the grid connection switch is confirmed to be disconnected, the system transitions from pre-islanded state to off-grid operation state. When the frequency deviation, frequency change rate, or voltage deviation of the common connection point all recover to within the first preset threshold and the duration exceeds the second preset time, the system returns from the weak network support state to the grid-connected operation state. When the upper-level power grid is detected to have recovered and the conditions for reconnection to the grid are met, the system will switch from off-grid operation to reconnection preparation state. When the voltage, frequency, and phase angle synchronization errors of the local side and the grid side all meet the preset synchronization threshold, the system transitions from the reconnection preparation state to the reconnection execution state.

[0043] Specifically, the transition between different operating states adopts a joint criterion of "threshold combination + duration judgment + external event signal". Among them, the disconnection command signal can be an external signal issued by the superior protection device, station control system or energy management system; or, it can be an internal signal generated by the coordination control layer after joint judgment based on the voltage drop depth at the point of common coupling, the rate of frequency change, the fault duration and protection action information.

[0044] The internally generated disconnection command signal satisfies one or a combination of the following exemplary criteria: the voltage drop at the point of common coupling exceeds a preset percentage of the rated value and lasts for a third preset duration; the frequency change rate exceeds a preset threshold and lasts for a fourth preset duration; or the protection device issues a fault section identification result and determines that disconnection is necessary.

[0045] Specifically, the internally generated disconnection pre-command signal is generated by the disconnection prediction logic of the coordinated control layer. It compares the PCC voltage, frequency, frequency change rate, and protection device action information at the point of common coupling (PCC) with preset thresholds. The PCC voltage deviation, frequency change rate, and fault duration are calculated to form voltage drop criteria, frequency change rate criteria, and protection action criteria, respectively. When any criterion is met, or multiple criteria are met according to a preset logic combination, the coordinated control layer outputs the disconnection pre-command signal. This disconnection pre-command signal serves as the input to the unified state machine, enabling the system to transition from a weak grid support state to a pre-islanded state, and triggering subsequent actions such as controller hot standby, state mapping, hydropower reserve pre-release, photovoltaic power curtailment preparation, and grid connection switch disconnection preparation.

[0046] For example, when the PCC voltage drops by more than 10% to 40% of the rated voltage and lasts for 20ms to 500ms, or when the frequency change rate exceeds 0.5Hz / s to 5Hz / s and lasts for a preset duration, an internal disconnection command signal can be triggered.

[0047] This invention covers the entire process of grid connection, weak grid connection, pre-islanding, off-grid connection and reconnection of the hydro-solar-storage complementary system based on a unified state machine, which improves the continuity of mode switching and the integrity of control logic, and quickly determines the current operating status, whether a state switch is required, and the target state to which it needs to switch.

[0048] In some possible implementations, based on the day-ahead scheduling plan, intraday correction results, real-time operating status, and a preset unified state machine of the hydro-solar-storage complementary system, a set of cross-layer control parameters corresponding to each operating status is generated, including: S102-1. Generate the energy storage baseline power, hydropower baseline power, and photovoltaic baseline power based on factors including the day-ahead dispatch plan, intraday correction results, load forecast, photovoltaic forecast, hydropower available output, energy storage SOC, equipment capacity constraints, operating costs, and supply guarantee requirements. S102-2. Based on the energy storage baseline power, hydropower baseline power, and photovoltaic baseline power, and combined with the real-time operating status and the preset unified state machine, further generate the control boundary parameters for the lower-level control. The control boundary parameters include at least: the upper limit of energy storage inertia support, the upper limit of energy storage droop support, the upper limit of energy storage recovery power, the minimum state of charge threshold for switching preparation, the hydropower reserve release slope, the reserved power for photovoltaic auxiliary support, and the reconnection synchronization threshold.

[0049] Specifically, such as Figure 4 The diagram shows the process of generating and calling cross-layer control parameter sets.

[0050] In step S102-1 above, the baseline power plan includes energy storage baseline power, photovoltaic baseline power, and hydropower baseline power. It is generated by the energy management system based on factors such as the day-ahead dispatch plan, intraday correction results, load forecast, photovoltaic forecast, available hydropower output, energy storage SOC, equipment capacity constraints, operating costs, and supply guarantee requirements. This baseline power plan is used to characterize the reference value of the normal operating power of each device during the current dispatch cycle.

[0051] For example, the baseline power plan is generated using a commonly used rolling optimization scheduling method, specifically linear programming, quadratic programming, or mixed-integer linear programming. Within each scheduling cycle, the energy management layer uses the day-ahead scheduling plan and intraday correction results as a reference plan. It then transforms load forecasting, photovoltaic forecasting, available hydropower output, energy storage SOC, equipment capacity constraints, operating costs, and supply requirements into the inputs, constraints, and objective function terms of the optimization model, respectively, to obtain the energy storage baseline power, photovoltaic baseline power, and hydropower baseline power for the current cycle.

[0052] In specific processing, the first step is to follow the day-ahead scheduling plan. and intraday correction Generate current scheduling reference value :

[0053] Then, based on the baseline power of hydroelectric power P hyd,base ( t ), photovoltaic baseline power P pv,base ( t ), energy storage baseline power P ess,base ( t Let be the variable to be determined, with discharging as positive and charging as negative, and establish a power balance relationship. During grid-connected operation, the following condition must be met:

[0054] Among them, P grid (t) represents the exchange power between the hydro-solar-storage complementary system and the external power grid. It can be defined that purchasing power from the external power grid is positive and sending power to the external power grid is negative. L for (t) represents the predicted load power at the current scheduling time.

[0055] In off-grid operation or pre-island supply guarantee scenarios, it can enable P grid (t)=0. This means that the local load demand is met by hydropower, photovoltaic power and energy storage, without relying on external power grid.

[0056] Based on the above constraints, the energy management system establishes an objective function to solve for the baseline power plan, aiming to minimize the weighted sum of operating costs, curtailment costs, energy storage degradation costs, deviation from the reference plan penalty, and supply guarantee penalty. For example, the objective function can be expressed as:

[0057] Where J is the objective function value of the baseline power plan, and C h C represents the hydropower operating cost or hydropower regulation cost coefficient. cur It is the light-discarding penalty coefficient, P pv,cut (t) represents the curtailed power, which can be determined by the difference between the predicted available photovoltaic power and the photovoltaic baseline power, C ess C is the energy storage charging and discharging attenuation cost coefficient. dev P is the penalty factor for deviating from the scheduling reference plan. sys (t) represents the sum of the baseline power of hydropower, photovoltaic power, and energy storage, C shed P is the penalty factor for unpowered loads. shed (t) represents the power of the unpowered load.

[0058] By solving the objective function described above, the baseline power plan for the current scheduling cycle is obtained, which consists of the baseline power of hydropower, the baseline power of photovoltaic power, and the baseline power of energy storage. When the next scheduling cycle arrives, the energy management system re-executes the above rolling optimization process based on the latest load forecast, photovoltaic forecast, available hydropower output, and energy storage SOC, thereby achieving dynamic updates to the baseline power plan.

[0059] In step S102-2 above, the control boundary parameters are lower-level control constraint parameters generated based on the baseline power plan above, combined with the real-time operating status and the unified state machine.

[0060] Among them, the upper limit of energy storage inertia support, the upper limit of energy storage droop support, and the upper limit of energy storage recovery power are calculated based on the rated power of energy storage, the current SOC, the SOC safety boundary, the current baseline power, and the switching preparation requirements; the minimum SOC threshold for switching preparation is determined based on the lower limit of energy storage safety, the energy required for future isolated supply periods, and the safety margin; the hydropower reserve release slope is determined based on the allowable ramp rate of the hydropower unit, the current head and water level, the adjustable capacity, and the current operating status; the reserved power for photovoltaic auxiliary support is determined based on the current maximum available output of photovoltaic, the baseline output, and the load reduction margin; and the reconnection synchronization threshold is determined based on the allowable voltage, frequency, and phase angle errors before the grid connection switch is closed.

[0061] Therefore, the cross-layer control parameter set generated in step S102 is not a simple baseline power plan, but a comprehensive parameter set including "baseline power plan + dynamic support boundary + switching preparation constraint + synchronization control threshold", which is used to ensure that the upper-layer optimized scheduling results can be safely executed by the lower-layer control in scenarios such as weak network disturbance, grid-connected to off-grid, and off-grid to grid-connected.

[0062] The cross-layer control parameter set of the present invention It can be written as:

[0063] in, This represents the baseline power for energy storage. Baseline power for photovoltaics; Baseline power for hydropower; The upper limit is supported by the energy storage inertia. This serves as the upper limit for the energy storage droop support. The upper limit of energy storage recovery power; A minimum state-of-charge threshold is prepared for switching; For hydropower reserve release slope; Reserve power for photovoltaic auxiliary support; These are the voltage, frequency, and phase angle synchronization thresholds for reconnection to the grid.

[0064] In some possible implementations, the upper limit of energy storage inertia support, the upper limit of energy storage droop support, and the upper limit of energy storage recovery power are determined based on the allocation coefficients related to the current operating state and the available rapid support power of energy storage, respectively. The allocation coefficients related to the current operating state are determined based on frequency deviation, continuous power deficit, hydropower replacement progress, or photovoltaic auxiliary support margin. The minimum state of charge threshold for switching preparation is obtained by superimposing the energy storage safety lower limit, the energy required for future islanded supply, the energy for rapid support during switching, and the safety margin. The hydropower reserve release slope is determined by the physical climbing ability of the hydropower unit and the current adjustable capacity. The reserved power for photovoltaic auxiliary support is determined by the current maximum available photovoltaic output, the photovoltaic baseline output, and the allowable load derating margin. The reconnection synchronization threshold is pre-set according to the synchronization requirements of the grid-connection switch, protection device and power grid.

[0065] The calculation methods for each control boundary parameter are described below.

[0066] (1) Upper limit of energy storage inertia support: It is mainly determined based on the rated power of energy storage, the current baseline power, the energy storage SOC margin, the charging and discharging power constraints, and the switching preparation SOC requirements. First, calculate the remaining callable rapid support power of energy storage after meeting the baseline power and SOC safety constraints, and then determine the upper limit of inertia support based on the inertia support allocation coefficient under the current operating state.

[0067] First, calculate the rapid support power margin that energy storage can still be deployed after meeting the baseline power and switching readiness requirements:

[0068] in, Energy storage can currently provide rapid power support. This is the rated power of the energy storage. P ess,base (t) represents the baseline power of energy storage, assuming discharge is positive and charging is negative. The callable power is determined by the current SOC and the SOC security boundary. To estimate the power available after meeting the minimum SOC required for switching, the following can be used:

[0069] Where SOC(t) is the current state of charge of the energy storage, SOC sw，min (t) is the minimum SOC threshold prepared for handover, E ess For the rated energy capacity of energy storage, η dis For energy storage and discharge efficiency; T sup Set the preset duration of rapid support.

[0070] Upper limit of energy storage inertia support α in (s) is the energy storage inertia support allocation coefficient under the current operating state s.

[0071] (2) Upper limit of energy storage droop support: mainly determined based on the remaining available rapid support power of energy storage, current frequency deviation, SOC constraints and switching preparation requirements.

[0072] Upper limit of energy storage droop support α dr (s) is the energy storage droop support allocation coefficient under the current operating state s.

[0073] When the frequency deviation is large and the energy storage SOC margin is sufficient, the upper limit of the droop support is increased; when the energy storage SOC is close to the minimum SOC threshold for switching preparation, the upper limit of the droop support is decreased.

[0074] (3) Upper limit of energy storage recovery power: mainly determined based on the current SOC of energy storage, target baseline power, charging and discharging power limit, allowable regression slope and energy storage lifetime constraint, used to limit the speed at which energy storage returns to the baseline operating point from the dynamic support state after the disturbance ends.

[0075] Energy storage recovery power limit α rec (s) is the energy storage recovery power allocation coefficient under the current operating state s.

[0076] α in (s), α dr (s), α rec (s) represent the allocation coefficients under the current running state s, which can be determined by preset tables, real-time correction or rolling optimization, and the value range is 0 to 1.

[0077] In practical implementation, these three allocation coefficients can be determined in three ways: First, pre-set basic lookup values ​​based on operating states such as grid-connected operation, weak grid support, pre-islanding, off-grid operation, and reconnection preparation (commonly used); Second, correct the basic values ​​online based on real-time frequency change rate, frequency deviation, SOC margin, and equipment availability; Third, in intraday or real-time rolling optimization, optimize the allocation of available rapid support power for energy storage among inertia support, droop support, and recovery power channels to directly obtain the corresponding allocation coefficients.

[0078] Among them, for α in(s) is mainly determined based on the frequency change rate, the current operating mode, and the energy storage SOC margin. For example, when the system is in a weak grid support or pre-islanding state and the frequency change rate is large, the coefficient is increased to increase the energy storage's inertia support capability for rapid frequency changes; when the system is in a normal grid connection or reconnection phase, or when the energy storage SOC is close to the minimum SOC threshold for switching preparation, the coefficient is decreased.

[0079] Specifically, the preset inertia support foundation allocation coefficient α under different operating modes can be obtained by looking up a table based on the current operating mode s. in,0 (s), where 0.2 is used for grid-connected operation, 0.45 for weak network support, 0.5 for pre-islanding, 0.35 for off-grid operation, and 0.15 for reconnection preparation or reconnection execution. Then, the absolute value of the rate of change of the PCC frequency at time t is calculated. , This is the measured frequency at the point of common coupling (PCC). The energy storage SOC margin can be calculated as follows: Where SOC(t) is the current state of charge of the energy storage; SOC sw,min (t) represents the minimum SOC threshold for handover.

[0080] When the rate of change of frequency is large, increasing α in,0 (s), when the SOC margin is small, reduce α in,0 (s). For example: if r(t) > 1Hz / s, then increase by 0.1, M soc If (t) < 10%, then reduce by 0.15, ensuring the corrected value falls within the range of [0.1, 0.6]. When the frequency deviation is large and the system requires energy storage to provide continuous active power regulation, increase the coefficient; when hydropower reserve release has taken over the continuous balancing task from energy storage, or when photovoltaics has a large auxiliary support margin, the coefficient can be appropriately reduced.

[0081] For α dr (s) is mainly determined based on frequency deviation, continuous power deficit, hydropower succession progress, and photovoltaic auxiliary support margin. When the frequency deviation is large and the system requires energy storage to provide continuous active power regulation, the coefficient is increased; when hydropower reserve release has taken over the continuous balancing task from energy storage, or when photovoltaic has a large auxiliary support margin, the coefficient can be appropriately reduced.

[0082] Specifically, the base value α can be obtained by looking up a table based on the current operating mode s. dr,0 (s), for example, 0.2 for grid-connected operation, 0.45 for weak network support, 0.5 for pre-islanding, 0.35 for off-grid operation, and 0.15 for reconnection preparation or reconnection execution. Then calculate the frequency deviation. f PCC (t) represents the measured frequency at the common junction point PCC, f refUse the frequency reference value; calculate the continuous power deficit. , where P for L (t) represents the predicted load power; P hyd,base (t) represents the baseline power of the hydropower station; P pv,base (t) represents the photovoltaic baseline power; P ess,base (t) represents the energy storage baseline power; P grid (t) represents the power exchanged between the system and the external power grid, with positive for power purchase and negative for power transmission; P is the power exchanged when the system is disconnected from the grid. grid (t)=0; Then, calculate the hydropower succession schedule. Δ Phyd,rel (t) represents the reserve increment that has already been released by hydropower. When γ h The closer (t) is to 1, the closer hydropower is to completing its role in continuously supporting energy storage. Calculate the photovoltaic auxiliary support margin. P ava pv (t) represents the maximum available photovoltaic output.

[0083] Corrections are made based on the above calculation results. For example, if |Δf(t)|>0.2Hz, it indicates a large frequency deviation, α dr,0 (s) increases by 0.1; ΔP def (t)>2MW indicates a persistent power deficit, α dr,0 (s) increased by 0.05; γ h (t)>0.7, indicating that hydropower has basically taken over, α dr,0 (s) Decrease by 0.10 (if < 0.7, generally take 0, not a positive value); P pv,res (t)≥0.5ΔP def (t) indicates that photovoltaics has significant auxiliary support capabilities, α dr,0 (s) decrease by 0.05pv (if <0.5ΔP) def (t), which is generally taken as 0 and not as a positive value.

[0084] For example, assuming the energy storage rated power is 10MW and the current baseline power is 3MW discharge, then the rated power margin is 7MW; if the available power after adjusting for current SOC and switching preparation SOC constraints is 6MW, then P ava ess,fast =6MW. Under weak grid support conditions, if α in =0.4、α dr =0.5、α rec =0.1, then the upper limit of inertia support is 2.4MW, the upper limit of droop support is 3.0MW, and the upper limit of recovery power is 0.6MW.

[0085] (4) Minimum SOC threshold for switching preparation: mainly determined based on the lower limit of safe SOC of energy storage, the energy required for the planned islanded supply period in the future, the power reserve required for rapid support during grid-connected and off-grid switching, and the safety margin:

[0086] Among them, SOC sw,min (t) represents the minimum SOC threshold for handover preparation (handover preparation constraint); SOC min The lower limit of SOC for energy storage safety; ΔSOC island (t) represents the SOC reserve amount converted from the energy required for future isolated supply periods; ΔSOC sup (t) represents the SOC reserve required for rapid support during grid-connected / off-grid switching; ΔSOC marg For safety margin.

[0087] (5) Hydropower standby release slope: mainly determined based on the hydropower unit's allowable ramp rate, current head and water level, current output, maximum allowable output, adjustable capacity and unit operating conditions, used to limit the speed at which hydropower gradually takes over the task of continuous power balance from energy storage.

[0088] First, calculate the adjustable capacity of water and electricity:

[0089] in, The current available capacity for hydropower is [to be increased]. The available hydropower output under the current head, water level, and unit operating conditions; P hyd,base (t) represents the baseline power of the hydropower station. Then, the hydropower reserve release slope is determined:

[0090] Among them, R hyd,rel (t) represents the hydropower reserve release slope; The physical allowable gradient for the hydroelectric generator unit; k hyd (s) represents the release coefficient under the current operating state s, with a value ranging from 0 to 1; T rel This is a preset replacement time.

[0091] (6) Reserved power for photovoltaic auxiliary support: mainly determined based on the current maximum available photovoltaic output, the photovoltaic baseline output, and the available load margin.

[0092] Among them, P pv,res (t) represents the reserved power for photovoltaic auxiliary support; P represents the maximum currently available output of photovoltaic power. pv,base (t) represents the photovoltaic baseline power; This parameter represents the allowable derating margin for photovoltaic (PV) systems, which is the upward adjustment space reserved to allow PV systems to operate below their maximum available output. When the maximum available PV output is higher than the baseline output, a portion of the difference can be used as reserve power for auxiliary support; when there is no derating margin for PV systems, this parameter can be set to zero.

[0093] (7) Reconnection synchronization threshold: This is mainly determined based on the allowable voltage amplitude error, frequency error, and phase angle error during the reconnection phase, and is set in conjunction with the synchronization requirements of the grid-connected switch, protection device, and power grid. It can be expressed as: Permissible voltage amplitude difference threshold for grid reconnection

[0094] Reconnection allowed frequency difference threshold

[0095] Permissible phase angle difference threshold for reconnection

[0096] in, These are the allowable voltage values ​​for grid-connected switches or circuit breakers, the allowable voltage values ​​for protection devices, and the preset voltage values ​​for control strategies, respectively. These are the allowable frequency values ​​for grid-connected switches or circuit breakers, allowable frequency values ​​for protection devices, and preset frequency values ​​for control strategies, respectively. These are the allowable phase angle values ​​for grid-connected switches or circuit breakers, allowable phase angle values ​​for protection devices, and preset phase angle values ​​for control strategies, respectively. The grid-connected switch is only allowed to be closed when the voltage, frequency, and phase angle errors on both the microgrid side and the grid side meet the corresponding synchronization thresholds.

[0097] Where t is the time index. These are the microgrid-side voltage, frequency, and phase angle. These are grid-side voltage, frequency, and phase angle. These are the synchronization thresholds corresponding to voltage error, frequency error, and phase angle error, respectively.

[0098] In the above implementation, step S103 mainly involves determining the state switching of the unified state machine based on the running state variables of the common connection point, determining the current running state, and calling the cross-layer control parameter set corresponding to the current running state.

[0099] Specifically, the voltage deviation, frequency deviation, and rate of change of the point of common coupling (PCC) are determined based on the operational status parameters of the PCC. In grid-connected operation, weak grid support, and pre-islanding assessment, the voltage deviation refers to the deviation between the measured voltage at the PCC and the rated voltage or the voltage reference value given by the coordinated control layer. In the reconnection phase, it refers to the deviation between the voltage on both sides of the grid-connected switch, i.e., the voltage on the local microgrid side and the voltage on the external power grid side.

[0100] In the judgment of grid-connected operation, weak grid support, pre-islanding and off-grid operation, frequency deviation refers to the deviation between the measured frequency at the point of common coupling (PCC) and the rated frequency or the frequency reference value under the current mode; in the reconnection phase, it refers to the deviation between the local microgrid side frequency and the external grid side frequency.

[0101] The frequency change rate refers to the rate of change of the measured frequency at the point of common coupling (PCC) over time. When the system is in an off-grid operation state, this frequency change rate corresponds to the rate of change of the local public AC bus or the microgrid side system frequency.

[0102] Therefore, in the state machine switching judgment, the weak grid support and pre-islanding stages are mainly based on the deviation of the measured voltage / frequency of the PCC relative to the rated or reference value, as well as the PCC frequency change rate; while the reconnection stage is mainly based on the voltage, frequency and phase angle synchronization deviation between the microgrid side and the grid side.

[0103] Based on the voltage deviation, frequency deviation, frequency change rate, disconnection command, grid restoration signal and synchronization criterion of the common coupling point, the current operating state of the unified state machine is determined, and the cross-layer control parameter set corresponding to the current operating state is obtained from the energy management layer.

[0104] In the above implementation, for step S104, the main arbitration dynamically supports the increment and determines the energy storage output command.

[0105] In embodiments of the present invention, the energy storage output command is constructed as the result of the coordination between the baseline power plan and the dynamic support increment, wherein the baseline power calculation comes from the upper-level optimization scheduling result, and the dynamic support increment is generated by the frequency deviation, the frequency change rate and the DC bus voltage deviation.

[0106] The energy storage output command is the final active power reference value issued by the coordination control layer to the energy storage converter or energy storage controller, used to control the charging and discharging power of the energy storage system at the current moment. This command integrates the baseline power component given by the upper-level optimized scheduling and the dynamic support increment component generated by frequency and voltage disturbances, and is obtained after processing by SOC constraints, power limiting, switching preparation constraints, and arbitration rules under the current operating state. Its function is to ensure that the energy storage operates in accordance with the economic dispatch results during normal operation, and to provide rapid frequency and voltage support during disturbances or grid connection / off-grid switching, while preventing dynamic support actions from encroaching on the energy reserves required for subsequent off-grid operation.

[0107] The baseline power plan is the energy storage baseline power obtained in step S103, which is P in the current state cross-layer control parameter set. ess,baseThis parameter is obtained by the energy management layer or the upper-level optimization and scheduling module based on the day-ahead scheduling plan, intraday correction results, real-time operating status, load forecast, photovoltaic forecast, hydropower available output, energy storage SOC, equipment capacity constraints, operating costs, curtailment costs, energy storage attenuation costs, and switching preparation constraints. It represents the reference value of normal economic operating power of energy storage when there is no disturbance in the current scheduling cycle.

[0108] The present invention obtains the final energy storage output command by calling the effective baseline power in the current state obtained in step S103 and superimposing or arbitrating the dynamic support increment on it.

[0109] In some possible implementations, based on the cross-layer control parameter set of the current operating state, the dynamic support increment is arbitrated to determine the energy storage output command, including: S104-1. Determine the dynamic support increment based on the frequency deviation, frequency change rate, and DC bus voltage deviation of the hydro-solar-storage complementary system. S104-2. When the dynamic support increment is consistent with the energy storage baseline power direction in the cross-layer control parameter set of the current operating state, the baseline power is superimposed on the dynamic support increment within the range of available rapid support power for energy storage to obtain the energy storage output command. S104-3 When the dynamic support increment is opposite to or conflicts with the energy storage baseline power direction in the cross-layer control parameter set of the current operating state, arbitration is carried out according to the preset arbitration rules based on the current operating state to determine the energy storage output command; wherein, the energy storage output command is constrained by the control boundary parameters.

[0110] Specifically, in step S104-1 above, the dynamic support increment includes the inertia support increment, the droop support increment, and the DC bus voltage compensation increment.

[0111] For example, with the discharge power of the energy storage system as the positive direction and the charging power as the negative direction, the following deviation is defined: ,in, For frequency deviation, The measured frequency at the common junction point (PCC) This is a frequency reference value; ,in, This refers to the DC bus voltage deviation. This is the measured voltage of the DC bus. This is the reference value for the DC bus voltage; Then inertia supports the increment It can be represented as:

[0112] in, To support the upper limit of energy storage inertia, The inertia support transfer function, This represents the rate of change of frequency at the point of common junction (PCC).

[0113] Incremental droop support It can be represented as:

[0114] in, This is the upper limit of the energy storage droop support. For the drooping support transfer function.

[0115] DC bus voltage compensation increment It can be represented as:

[0116] in, This is the DC voltage compensation power limiting value. This is the DC voltage compensation transfer function.

[0117] function This represents a limit operation, defined as: calculating the expression The value, and compare it with the lower limit. and upper limit ( Compare the results and restrict them to closed intervals. Inside. like Then take ;like Then take Otherwise take itself.

[0118] In this embodiment, the DC bus voltage compensation increment is preferably used as a DC-side stability compensation component inside the energy storage converter to participate in arbitration. It is mainly used to suppress DC bus voltage deviation and maintain the energy balance of the converter, and is not used as a long-term continuous power source. Its output should be constrained by the current operating state, the total dynamic support limit, and the equipment safety boundary.

[0119] Dynamic support increment It can be represented as:

[0120] If we further consider the smooth regression transition process during the disturbance recovery phase, we can add the recovery power increment. At this point, the dynamic support incremental expansion becomes:

[0121] To ensure that the underlying dynamic support does not encroach on the energy and power margin required for switching preparation, the following must be met:

[0122] in, This refers to the available rapid backup power of energy storage after meeting the current baseline power, charge / discharge constraints, and switching readiness requirements. SOC(t) represents the current state of charge of the energy storage. sw,min (t) represents the minimum SOC threshold for handover.

[0123] In step S104-2 above, when the dynamic support increment is aligned with the energy storage baseline power direction, the dynamic support increment and the energy storage baseline power are superimposed within the available rapid support power range, and an energy storage output command is output. Specifically, taking energy storage discharge as positive and charging as negative as an example, let the energy storage baseline power be denoted as P. ess,base The dynamic support increment is denoted as ΔP. ess,dyn When both satisfy P ess,base ·ΔP ess,dyn When the value is greater than 0, it indicates that both signals have the same sign, meaning both require energy storage discharge or both require energy storage charging, and are therefore considered to be in the same direction. In this case, energy storage output commands can be superimposed within the range of rated energy storage power, SOC boundary, and currently available fast support power.

[0124] In step S104-3 above, when the dynamic support increment and the energy storage baseline power direction are opposite and there is a directional conflict, the process is handled according to the preset arbitration rules based on the current operating status. The arbitration rules include at least one or more of the following: dynamic support priority coverage, directional limitation correction, or limiting output with switching pre-constraints. Specifically, when both satisfy P... ess,base ·ΔP ess,dyn When the value is less than 0, it indicates that the two signals are opposite, meaning one requests energy storage charging while the other requests energy storage discharging, and are therefore judged to be in opposite directions. When the directions are opposite and the dynamic support increment reaches a preset effective threshold, or when the two signals combined would cause the energy storage charging / discharging direction to reverse, weaken the necessary frequency support, touch the energy storage power / SOC boundary, or affect the switching preparation SOC, it is judged that there is a directional conflict.

[0125] In the event of directional conflicts, this invention employs different arbitration rules based on the current operating state.

[0126] In grid-connected operation, priority is given to maintaining the economic dispatch baseline and the switching preparation SOC, and the dynamic support increment is subject to directional restriction correction or amplitude limiting. When the frequency deviation or frequency change rate exceeds the severe threshold, dynamic support is allowed to cover part of the baseline power for a short period of time.

[0127] Under weak grid support conditions, the priority of dynamic support increments is increased. When there is a directional conflict, the priority of dynamic support increments is set to be higher than the energy storage baseline power. However, the final energy storage output command is still constrained by the energy storage rated power, SOC boundary, available fast support power, and switching reserve SOC.

[0128] In the pre-islanding state, dynamic support increment and switching preparation constraints are given priority at the same time, allowing energy storage to provide rapid support for grid-connected to off-grid transition. However, a limited output with switching preparation SOC constraints must be used to prevent excessive discharge of energy storage from affecting subsequent off-grid operation.

[0129] In off-grid operation, frequency stability takes priority. When the frequency deviation or frequency change rate is large, the dynamic support increment takes precedence over the energy storage baseline power. As hydropower reserves gradually take over and the frequency recovers, the weight of dynamic support gradually decreases, allowing the energy storage output to return to the baseline power.

[0130] During grid reconnection preparation and grid reconnection execution, synchronous tracking and power smoothing return are prioritized.

[0131] For directional conflicts, directional limiting correction or amplitude limiting output is generally used to avoid large changes in energy storage power that could lead to increased voltage, frequency, phase angle synchronization errors or grid connection impact.

[0132] The current operational status is determined according to the above arbitration rules. Arbitration function The final energy storage output command Not for baseline power With dynamic support total increment Instead of performing unconditional direct algebraic addition, it depends on the current running state. Arbitration function The arbitration process, which generates a comprehensive decision, can be represented as follows:

[0133] in, This is the final energy storage output command output by the arbitration function. Indicates the current running status The corresponding arbitration function is used to limit and correct the energy storage output command based on multiple factors such as dynamic support priority, energy storage state of charge (SOC) boundary constraints, energy storage rated power, available fast support power, and switching preparation SOC requirements, so as to ensure the safe and stable operation of the system.

[0134] It should be noted that the energy storage output command is simultaneously constrained by control boundary parameters such as the current mode, state of charge threshold, available power margin, hydropower succession progress, and switching preparation requirements. For example, the final energy storage output cannot exceed the PCS and the battery's current allowable charge and discharge power. After energy storage output, the SOC cannot exceed the safety upper and lower limits. In cases of switching risks, pre-islanding, or off-grid power supply requirements, the SOC must also be greater than the set safety lower limit to ensure energy reserves for subsequent off-grid operation and grid-connected / off-grid switching. The coordination control layer constrains the energy storage output command based on these control boundary parameters and arbitration rules to determine the final energy storage output command, thereby preventing dynamic support from encroaching on the energy and power reserves required for subsequent mode switching.

[0135] In general, when the SOC is sufficient, the available power margin is sufficient, and the dynamic support increment is consistent with the energy storage baseline power direction, the arbitration result can be the power command superimposed by the two. When the available energy storage power is insufficient, the arbitration result is limited to the range of the current available charging and discharging power of the energy storage. When the SOC is close to the minimum SOC threshold for switching preparation and the dynamic support requires the energy storage to continue discharging, the arbitration result reduces or prohibits the dynamic support increment in the discharge direction. When the grid support is weak or the operation is off-grid and the frequency deviation is serious, the arbitration result allows the dynamic support to cover the baseline power direction for a short time. In the pre-islanding state, the arbitration result must simultaneously meet the switching preparation SOC and the fast support power reservation requirements. After the hydropower replacement is gradually completed, the arbitration result causes the energy storage dynamic support increment to gradually withdraw and return to the baseline power. In the reconnection phase, the arbitration result restricts sudden changes in energy storage power to avoid the expansion of synchronization error and grid connection impact. Therefore, the constraint of the control boundary parameters on the energy storage output command is not a single limit, but an arbitration rule composed of the current mode priority, SOC safety boundary, available power margin, hydropower replacement progress and switching preparation requirements. This is used to ensure that the energy storage can provide rapid support without overdrawing the energy and power reserves required for subsequent off-grid switching.

[0136] The final energy storage output command will be sent to the energy storage converter PCS as its active power reference value.

[0137] In the above implementation, step S105 mainly involves switching control between the grid and the off-grid.

[0138] The main function of grid-connected / off-grid switching control is to switch the current operating state to the target state. During the grid-connected to off-grid transition, the grid controller to be put into operation first enters a hot standby tracking state; the coordination control layer maps the internal active, reactive, phase, and integral states of the original grid-connected controller to the grid controller according to the state mapping function; then the grid-connected switch is disconnected, and the grid controller takes over the local bus frequency and voltage control. During the off-grid to grid-connected transition, the local grid unit performs synchronous tracking of the grid-side voltage, frequency, and phase angle; when the synchronization error meets the set threshold, the grid-connected switch is closed, and the control is smoothly returned to the main grid reference according to a preset slope.

[0139] In the process of grid-connected and off-grid switching control, this invention uses energy storage output commands for the fastest dynamic support, while hydropower gradually takes over the energy storage control unit in a limited ramp-up manner to undertake the continuous balancing task. When photovoltaic power has a reserved load reduction margin, it participates in auxiliary support within the reserved range, thereby avoiding long-term high-power output of energy storage.

[0140] In some possible implementations, grid-connection control is executed according to energy storage output commands, including: When the hydro-solar-storage complementary system enters the weak grid support state, pre-island state, or off-grid operation state, the energy storage control unit assumes frequency support according to the energy storage output command, and the hydro power control unit controls the hydro generator to gradually increase the output according to the pre-generated reserve release slope to take over the continuous power shortage of the energy storage control unit. When the current available maximum output of the photovoltaic control unit is greater than the photovoltaic baseline power, the difference between the current available maximum output and the photovoltaic baseline power is used as the reserved power for photovoltaic auxiliary support. When the frequency of the hydro-photovoltaic-storage complementary system is lower than the reference value or there is an active power deficit, the photovoltaic control unit increases the photovoltaic output within the range of the reserved power for photovoltaic auxiliary support.

[0141] Specifically, when the hydro-solar-storage complementary system enters a weak grid support state, a pre-islanding state, or an off-grid operation state, the energy storage output command is prioritized to provide frequency support for the system. Hydropower then gradually assumes the continuous balancing task according to the reserve release slope. That is, the energy storage control unit first provides rapid frequency support, and the hydropower units subsequently increase their output gradually according to the pre-generated reserve release slope to take over the continuous power deficit from the energy storage. The hydropower reference power can be expressed as:

[0142] in, This represents the reference power of hydropower at the next moment; This represents the target power output to be replaced by hydropower. This represents the current reference power of hydropower. Represents the hydropower reserve release slope (unit: power / time); This represents the control step size or time interval; This represents the maximum allowable output of hydropower. The reference power for hydropower is constrained by the increment of hydropower reserve release and the reserve release slope.

[0143] When the photovoltaic power is currently available at its maximum power Greater than the photovoltaic baseline power given by the upper-level optimization The difference between the two can be used as the reserved power for photovoltaic auxiliary support. This reserved power for photovoltaic auxiliary support can be expressed as... When the frequency of the hydro-solar-storage complementary system is lower than the reference value or there is a power deficit, the coordination control layer increases the photovoltaic output within the range of the reserved power for photovoltaic auxiliary support, for example... And satisfy: Therefore, photovoltaic auxiliary support does not increase output indefinitely, but rather participates in active power supplementation within the reserved load reduction capacity. The photovoltaic reference power is constrained by the incremental power of photovoltaic auxiliary support and the reserved power of photovoltaic auxiliary support.

[0144] In this embodiment, photovoltaic auxiliary support is mainly used for active power supplementation on time scales of seconds and above, and is not the sole implementer of millisecond-level inertia support. If necessary, auxiliary support can be achieved by limiting the MPPT operating point, switching to power point tracking mode, or employing fast active reference tracking control.

[0145] In the above implementation, after step S105, the method further includes: establishing a two-layer optimization scheduling model that considers operating costs, curtailment costs, energy storage attenuation costs, and switching executability constraints, and performing scheduling optimization by solving the two-layer optimization scheduling model.

[0146] In some possible implementations, the two-layer optimization model includes an upper-layer optimization model and a lower-layer rolling optimization model; The upper-level optimization model is used to optimize the baseline power plan and reserve configuration for the day or day. The upper-level optimization model takes the minimum hydropower operation cost or hydropower regulation cost, the minimum curtailment of solar power, the minimum energy storage attenuation cost, and the minimum risk of non-executability of state switching as the optimization objectives. The lower-level rolling optimization model is used to correct the cross-level control parameter set according to the real-time status and limit the impact of dynamic support increment on energy storage lifetime and subsequent state switching feasibility. The lower-level rolling optimization model takes the minimum frequency deviation, the minimum frequency change rate, the minimum DC surface voltage deviation, the minimum deviation between energy storage output command and energy storage baseline power, and the minimum risk of real-time state switching not being executable as optimization objectives. Among them, the upper-level optimization model and the lower-level rolling optimization model jointly satisfy the power balance constraint, equipment capacity constraint, energy storage SOC constraint, hydropower ramping constraint, photovoltaic available output constraint, minimum SOC constraint for switching preparation, energy storage available rapid support power constraint, and reconnection synchronization threshold constraint.

[0147] Specifically, the objective function of the upper-level optimization model for:

[0148] in, It refers to the operating cost or regulation cost of hydropower. It is the light abandonment penalty coefficient. It is the power of abandoned light; It is the energy storage attenuation cost coefficient; It is the baseline power of energy storage; It is to switch the penalty coefficient for non-executability risk; It switches the executable penalty item. Represents a time interval.

[0149] A penalty is incurred if the current SOC is lower than the minimum SOC required for switching, or if the available fast support power of the energy storage is lower than the fast support power required for the predetermined switching scenario.

[0150] The lower-level rolling optimization model is used to correct cross-level control parameters based on real-time operating status, and its objective function is... for:

[0151] in, For time indexing, It's a frequency deviation; It is the rate of change of frequency; It is the DC surface voltage deviation; It is the final output instruction of the energy storage system; This represents the baseline power for energy storage. It allows for real-time switching of executability penalty items; , These are dimensionless weighting coefficients.

[0152] It is understandable that the aforementioned cost coefficients and weighting coefficients can be preset based on operational economics, safety priority, equipment lifespan model, protection setting requirements, and historical operating data, or can be adjusted according to the operating status during the daily rolling optimization process. Specifically, the curtailment penalty coefficient can be determined based on the curtailment power loss or new energy consumption assessment requirements; the energy storage attenuation cost coefficient can be determined based on the energy storage battery cycle life, equivalent throughput power lifespan model, or unit throughput power loss cost; the switching non-executable risk penalty coefficient is used to increase the priority of switching safety constraints, and its value is usually higher than the weight corresponding to the simple economic cost item; the dimensionless weighting coefficients in the lower-level rolling optimization are used to adjust the relative priority between frequency deviation, frequency change rate, DC bus voltage deviation, energy storage deviation from baseline power, and switching risk. These weighting coefficients are all non-negative numbers and can be set through simulation tuning, engineering trial operation, historical disturbance data statistics, or expert experience.

[0153] In the above implementation, step S106 involves performing a succession completion determination, power regression, and closed-loop update.

[0154] The coordination and control layer gradually increases hydropower output according to the hydropower reserve release slope in the current parameter set to take over the continuous power balancing task from energy storage. Hydropower takeover is considered complete when one or a combination of the following conditions are met: 1. The absolute value of the increase in energy storage dynamic support decreases to within the preset threshold; 2. The system frequency deviation and frequency change rate recover to within the preset range and remain within the preset duration; 3. The actual output of hydropower has reached the current planned replacement target.

[0155] The current planned replacement target can be determined comprehensively based on the current load deficit, actual photovoltaic output, energy storage baseline power, and the progress of dynamic support withdrawal. Preferably, the replacement target can be represented as the power portion originally undertaken by energy storage and planned to be gradually taken over by hydropower in the system's continuous balancing task.

[0156] After the hydropower replacement is completed, energy storage will gradually shift from being primarily used for rapid support to being used as an auxiliary regulation system for necessary backup.

[0157] Once the system disturbance ends, the frequency recovers, or the mode switch is completed, the dynamic support increment and the hydropower reserve release increment gradually exit according to the preset regression slope, so that the equipment output returns to the latest optimized baseline power operating point, and the operating results are fed back to the energy management layer, forming a closed loop of "optimization-control-feedback-re-optimization".

[0158] Specifically, during the disturbance recovery phase, the arbitration function gradually reduces the dynamic support increment weight according to a preset regression slope, causing the energy storage output to return to the latest baseline power operating point. The disturbance recovery phase is a control phase or transition process within the unified state machine, encompassing various operating states such as grid-connected operation, weak grid support, pre-islanding, and off-grid operation. For example, in the weak grid support state, frequency and voltage gradually recover but have not yet fully returned to grid-connected operation; in the off-grid operation state, after hydropower gradually replaces energy storage, the dynamic support for energy storage exits; after reconnection, the grid-connected support weight for energy storage gradually decreases, returning to the grid-connected baseline power.

[0159] When the frequency deviation, frequency change rate, or voltage deviation recovers to the preset range and continues to meet the set time, or when the hydropower succession progress reaches the preset threshold, the coordination control layer sets the recovery flag in the current state to valid, entering the disturbance recovery control phase. In this disturbance recovery control phase, the unified state machine can remain in the weak grid support, off-grid operation, or reconnection execution state, but the arbitration function begins to reduce the dynamic support increment weight; that is, the dynamic support increment is adjusted to:

[0160] in, To adjust the weights, This is the adjusted dynamic support increment. In cases of severe disturbances... When the value approaches 1, dynamic support is fully involved; during disturbance recovery, The slope is gradually decreased according to the preset regression slope; after recovery is complete. Approaching 0, energy storage returns to baseline power.

[0161] At this point, the final energy storage output command still satisfies the power constraint, the SOC constraint, and the available fast support power constraint under the current state.

[0162] The method of the present invention will now be described in conjunction with specific state switching scenarios.

[0163] I. Grid-connected to off-grid switching scenarios Suppose a hydro-solar-storage complementary system is in grid-connected operation, with hydropower operating at the planned output, solar power operating at the predicted high output range, and energy storage operating in the medium-to-high SOC range with reserved power for rapid support.

[0164] When a fault occurs in the upstream power grid, causing a drop in PCC voltage accompanied by a rapid increase in the rate of frequency change, the hydro-solar-storage complementary system first transitions from grid-connected operation to a weak grid support state. At this time: 1) The coordination control layer calls the cross-layer control parameter set under weak network conditions to increase the upper limit of energy storage inertia support and the upper limit of droop support; 2) If there is reserved load-reducing capacity for photovoltaic power, then photovoltaic power will participate in auxiliary support within this range; 3) Hydropower will begin pre-starting power boosting according to the predetermined standby release slope.

[0165] When the voltage drop and frequency deviation further meet the pre-islanding criterion, the hydro-solar-storage complementary system enters the pre-islanding state. At this time: 1. The energy storage grid controller enters hot standby takeover mode; 2. The internal states of the original grid-connected controller are mapped to the grid-connected controller; 3. The photovoltaic system is switching from grid-connected power control to power limiting follower control in preparation. 4. Hydropower will continue to be released for standby use; 5. After the grid controller has stably established the local frequency and voltage reference, disconnect the grid connection switch.

[0166] After the grid connection switch is disconnected, the hydro-solar-storage complementary system enters off-grid operation. Energy storage establishes a local frequency and voltage reference within milliseconds, hydropower gradually takes over the continuous active power balancing task within seconds, and photovoltaic power maintains power-following mode. After the takeover is complete, energy storage transitions from primary support to auxiliary regulation with necessary margins.

[0167] Compared to traditional direct switching methods, this invention significantly reduces frequency drops and voltage fluctuations, and improves switching smoothness and power supply continuity because it completes cross-layer parameter calling, controller hot standby, water and electricity backup pre-release, and dynamic support arbitration before switching.

[0168] II. Off-grid to on-grid switching scenarios After operating off-grid for a period of time, the upstream power grid was detected to have recovered and met the conditions for reconnection. The hydro-solar-storage complementary system first entered the reconnection preparation state. The local grid-connected unit performed synchronous tracking control based on the collected grid-side voltage, frequency, and phase angle information. At the same time, the lower-level rolling optimization updated the cross-level control parameter set for the reconnection stage based on the current SOC, hydropower output, and load demand.

[0169] Once the errors in voltage amplitude, frequency, and phase angle between the local microgrid and the grid side meet the synchronization thresholds, the hydro-solar-storage complementary system enters the reconnection execution state and closes the grid connection switch at a selected time. After the grid connection switch is closed: 1) The local grid unit does not immediately withdraw, but maintains a short transition in parallel with the large power grid reference; 2) The coordination control layer gradually reduces the control weight of energy storage network according to the set slope; 3) Energy storage output gradually returns to the baseline power operating point; 4) The photovoltaic system has been restored from the power-limited follower mode to the grid-connected baseline operation mode; 5) Hydropower output will be restored to the grid connection plan according to the set regression slope.

[0170] Through the above process, phase abrupt changes, power surges, and circulating current problems during the reconnection of the hydro-solar-storage complementary system can be avoided.

[0171] Figure 5 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 5 As shown, the electronic device may include a processor 510, a communication interface 520, a memory 530, and a communication bus 540. The processor 510, communication interface 520, and memory 530 communicate with each other via the communication bus 540. The processor 510 can call logical instructions from the memory 530 to execute a cross-layer collaborative control and optimized scheduling method for a hydro-solar-storage complementary system provided in the above embodiments.

[0172] Furthermore, the logical instructions in the aforementioned memory 530 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0173] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute a cross-layer collaborative control and optimization scheduling method for a water-solar-storage complementary system provided in the above-described method embodiments.

[0174] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements a cross-layer collaborative control and optimized scheduling method for a hydro-solar-storage complementary system provided by the above methods.

[0175] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0176] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0177] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cross-layer collaborative control and optimal scheduling method for a hydro-solar-storage complementary system, characterized in that, include: Collect operational status data of the common connection point of the hydro-solar-storage complementary system; Based on the day-ahead scheduling plan, intraday correction results, real-time operating status, and preset unified state machine of the aforementioned hydro-solar-storage complementary system, a cross-layer control parameter set corresponding to each operating status is generated; wherein, the cross-layer control parameter set includes the baseline power plan of energy storage, hydropower, and photovoltaic, as well as control boundary parameters used to ensure the executability of dynamic support and state switching. The current operating state of the unified state machine is determined based on the operating state variables of the common connection point, and the cross-layer control parameter set of the current operating state is obtained. Based on the cross-layer control parameter set of the current operating state, the dynamic support increment is arbitrated to determine the energy storage output command; Execute and switch off-grid according to the energy storage output command; Once the on-grid / off-grid switching is complete, the dynamic support increment will be gradually withdrawn according to the preset regression slope.

2. The cross-layer collaborative control and optimal scheduling method for a hydro-solar-storage complementary system according to claim 1, characterized in that, The unified state machine includes grid-connected operation state, weak network support state, pre-islanding state, off-grid operation state, reconnection preparation state, and reconnection execution state; The switching method between the various operating states of the unified state machine is as follows: When any one of the frequency deviation, frequency change rate, or voltage deviation of the common connection point exceeds the first preset threshold, is less than the second preset threshold, and the duration exceeds the first preset time, the grid-connected operation state is switched to the weak grid support state. When any one of the frequency deviation, frequency change rate, or voltage deviation of the common connection point exceeds the second preset threshold, or when a disconnection command signal is received, the system switches from the weak network support state to the pre-islanding state. Once the grid connection switch is confirmed to be disconnected, the system transitions from pre-islanded state to off-grid operation state. When the frequency deviation, frequency change rate, or voltage deviation of the common connection point all recover to within the first preset threshold and the duration exceeds the second preset time, the system returns from the weak network support state to the grid-connected operation state. When the upper-level power grid is detected to have recovered and the conditions for reconnection to the grid are met, the system will switch from off-grid operation to reconnection preparation state. When the voltage, frequency, and phase angle synchronization errors of the local side and the grid side all meet the preset synchronization threshold, the system transitions from the reconnection preparation state to the reconnection execution state.

3. The cross-layer collaborative control and optimal scheduling method for a hydro-solar-storage complementary system according to claim 1, characterized in that, Based on the day-ahead scheduling plan, intraday correction results, real-time operating status, and preset unified state machine of the aforementioned hydro-solar-storage complementary system, a set of cross-layer control parameters corresponding to each operating status is generated, including: Based on factors including the day-ahead dispatch plan, intraday correction results, load forecast, photovoltaic forecast, hydropower available output, energy storage SOC, equipment capacity constraints, operating costs, and supply guarantee requirements, the energy storage baseline power, hydropower baseline power, and photovoltaic baseline power are generated respectively. Based on the energy storage baseline power, hydropower baseline power, and photovoltaic baseline power, control boundary parameters are generated in combination with the real-time operating status and the preset unified state machine. The control boundary parameters include at least: upper limit of energy storage inertia support, upper limit of energy storage droop support, upper limit of energy storage recovery power, minimum state of charge threshold for switching preparation, hydropower reserve release slope, reserved power for photovoltaic auxiliary support, and reconnection synchronization threshold.

4. The cross-layer collaborative control and optimal scheduling method for a hydro-solar-storage complementary system according to claim 3, characterized in that, The upper limit of energy storage inertia support, the upper limit of energy storage droop support, and the upper limit of energy storage recovery power are determined based on the allocation coefficients related to the current operating status and the available rapid support power of energy storage, respectively. The allocation coefficients related to the current operating status are determined based on frequency deviation, continuous power deficit, hydropower replacement progress, or photovoltaic auxiliary support margin. The minimum state of charge threshold for switching preparation is obtained by superimposing the energy storage safety lower limit, the energy required for future islanded supply, the energy for rapid support during switching, and the safety margin. The hydropower reserve release slope is determined by the physical ramping capability of the hydropower unit and the currently adjustable capacity. The reserved power for photovoltaic auxiliary support is determined by the current maximum available output of photovoltaic power, the baseline output of photovoltaic power, and the allowable load reduction margin; The reconnection synchronization threshold is pre-set according to the synchronization requirements of the grid-connection switch, protection device and power grid.

5. The cross-layer collaborative control and optimal scheduling method for a hydro-solar-storage complementary system according to claim 1, characterized in that, The step of arbitrating dynamic support increments based on the cross-layer control parameter set of the current operating state to determine energy storage output commands includes: Based on the operating status parameters of the common connection point, the frequency deviation, frequency change rate, and DC bus voltage deviation of the hydro-solar-storage complementary system are determined, and the dynamic support increment is calculated; wherein, the dynamic support increment includes the inertia support increment, the droop support increment, and the DC bus voltage compensation increment. When the dynamic support increment is consistent with the energy storage baseline power direction in the cross-layer control parameter set of the current operating state, the energy storage baseline power is superimposed on the dynamic support increment within the range of available rapid support power for energy storage to obtain an energy storage output command. When the dynamic support increment is opposite to the energy storage baseline power direction in the cross-layer control parameter set of the current operating state and there is a directional conflict, arbitration is carried out according to the current operating state and a preset arbitration rule to determine the energy storage output command. The energy storage output command is constrained by the control boundary parameters in the cross-layer control parameter set.

6. The cross-layer collaborative control and optimal scheduling method for a hydro-solar-storage complementary system according to claim 2, characterized in that, The off-grid switching control executed according to the energy storage output command includes: When the hydro-solar-storage complementary system enters a weak grid support state, a pre-island state, or an off-grid operation state, the energy storage control unit assumes frequency support according to the energy storage output command, and the hydropower control unit controls the hydropower unit to gradually increase output according to the pre-generated standby release slope to take over the continuous power shortage from the energy storage control unit. When the current available maximum output of the photovoltaic control unit is greater than the photovoltaic baseline power, the difference between the current available maximum output and the photovoltaic baseline power is used as the photovoltaic auxiliary support reserved power. When the frequency of the hydro-photovoltaic-storage complementary system is lower than the reference value or there is an active power deficit, the photovoltaic control unit increases the photovoltaic output within the range of the photovoltaic auxiliary support reserved power.

7. The cross-layer collaborative control and optimal scheduling method for a hydro-solar-storage complementary system according to claim 1, characterized in that, The method further includes: A two-layer optimization scheduling model is established, which considers operating costs, curtailment costs, energy storage attenuation costs, and switching feasibility constraints. The two-layer optimization model includes an upper-layer optimization model and a lower-layer rolling optimization model. The upper-level optimization model is used to optimize the baseline power plan and reserve configuration for the day or day. The upper-level optimization model takes the minimum hydropower operation cost or hydropower regulation cost, the minimum curtailment of solar power, the minimum energy storage attenuation cost, and the minimum risk of non-executability of state switching as the optimization objectives. The lower-level rolling optimization model is used to correct the cross-layer control parameter set according to the real-time status and limit the impact of the dynamic support increment on the energy storage lifetime and the feasibility of subsequent state switching. The lower-level rolling optimization model takes the minimum frequency deviation, the minimum frequency change rate, the minimum DC surface voltage deviation, the minimum deviation between the energy storage output command and the energy storage baseline power, and the minimum risk of real-time state switching not being executable as optimization objectives. The upper-level optimization model and the lower-level rolling optimization model together satisfy the following constraints: power balance constraint, equipment capacity constraint, energy storage SOC constraint, hydropower ramping constraint, photovoltaic available output constraint, minimum SOC constraint for switching preparation, energy storage available rapid support power constraint, and grid reconnection synchronization threshold constraint.

8. A cross-layer collaborative control and optimized scheduling system for a hydro-solar-storage complementary system, characterized in that, include: The energy management layer is used to generate cross-layer control parameter sets corresponding to each operating state based on the day-ahead scheduling plan, intraday correction results, real-time operating status, and preset unified state machine of the hydro-solar-storage complementary system. The cross-layer control parameter sets include the baseline power plans for energy storage, hydropower, and photovoltaics, as well as control boundary parameters to ensure the executability of dynamic support and state switching. The coordination control layer is used to collect the operating status data of the common connection point of the hydro-solar-storage complementary system; determine the current operating status of the unified state machine based on the operating status data of the common connection point, and obtain the cross-layer control parameter set of the current operating status from the energy management layer; arbitrate the dynamic support increment based on the cross-layer control parameter set of the current operating status, and determine the energy storage output command. Execute grid-connected / off-grid switching control according to the energy storage output command; after the grid-connected / off-grid switching is completed, gradually withdraw the dynamic support increment according to the preset regression slope; The physical device layer is used to execute the speed regulation and excitation control of the hydropower unit of the hydropower control unit, the photovoltaic inverter control of the photovoltaic control unit, the energy storage converter control of the energy storage control unit, and the energy storage battery management according to the instructions of the coordination control layer.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the cross-layer collaborative control and optimized scheduling method for the hydro-solar-storage complementary system as described in any one of claims 1 to 7.

10. A non-transitory 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 cross-layer collaborative control and optimization scheduling method for the hydro-solar-storage complementary system as described in any one of claims 1 to 7.

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