Power supply system

Abstract

Provided in the embodiments of the present application is a power supply system, the power supply system comprising a power converter and a controller. The power converter is configured to convert a direct current output by a photovoltaic module and / or an energy storage unit into an alternating current, and output same to a load or a power grid. The controller is configured to, on the basis of a target remaining electric quantity, power grid charging enabling, photovoltaic remaining electric energy distribution, energy storage unit discharging enabling, photovoltaic curtailment and a current remaining electric quantity of the energy storage unit, control the energy storage unit to simultaneously receive electric energy provided by the photovoltaic module and the power grid for charging, or control the energy storage unit to only receive electric energy provided by the photovoltaic module for charging; control the power converter such that after the load satisfies a power supply demand, the photovoltaic module preferentially charges the energy storage unit with remaining electric energy of the photovoltaic module, or preferentially supplies power to the power grid; control the power converter to convert the direct current output by the energy storage unit into the alternating current for discharge and output same to the load, or control the energy storage unit not to discharge; and control the photovoltaic module to perform photovoltaic curtailment, or output all electric energy.

Description

Power supply system

[0001] This application claims priority to Chinese Patent Application No. 202410799120.6, filed on June 20, 2024, entitled "Power Supply System", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of electronic power, and more particularly to a power supply system. Background Technology

[0003] In photovoltaic-storage-load microgrids, efficient energy management and optimized dispatch are core issues. Energy management involves real-time monitoring and forecasting of multiple aspects, including photovoltaic power generation, energy storage systems, and load demand, as well as the formulation and implementation of energy dispatch strategies based on this data. The complexity and real-time requirements of energy management increase the difficulty of technical implementation. Economic optimization of photovoltaic-storage-load microgrids requires comprehensive consideration of multiple factors, including equipment investment costs, operation and maintenance costs, and electricity trading revenue. Therefore, developing reasonable economic optimization models and algorithms to minimize microgrid operating costs and maximize revenue is a challenging technical problem. However, for photovoltaic-storage-load microgrid systems in residential, commercial, and industrial scenarios, due to factors such as small load size, high randomness, and inferior public grid signal quality compared to dedicated power grids, the control accuracy and cost optimization effects of traditional centralized large power grids or regional power grids cannot meet the needs of photovoltaic-storage-load microgrids. Summary of the Invention

[0004] This application provides a power supply system that can optimize the control accuracy of the power supply system's energy dispatch strategy and improve the cost optimization or revenue optimization effect.

[0005] In a first aspect, this application provides a power supply system, comprising a power converter and a controller. The power converter converts the direct current (DC) output from photovoltaic (PV) modules and / or energy storage units into alternating current (AC) for output to a load or the power grid. The controller is configured to, based on a target remaining power capacity, grid charging enable, PV remaining power allocation, energy storage unit discharge enable, PV curtailment, and the current remaining power capacity of the energy storage unit, control the energy storage unit to simultaneously receive power from both PV modules and the grid for charging, or control the energy storage unit to receive power only from the PV modules for charging; control the power converter to prioritize charging the energy storage unit with the remaining power of the PV modules after the load meets the power demand, or prioritize supplying power to the grid; control the power converter to convert the DC output from the energy storage unit into AC for output to the load, or control the energy storage unit not to discharge; and control the PV modules to stop outputting power or continue outputting power when the remaining power capacity of the energy storage unit reaches its maximum value and the grid's power supply reaches a power threshold.

[0006] In this application, the controller in the power supply system determines the control strategy for the power converter and energy storage unit for the current control period by combining the control command set corresponding to each control period and the remaining power of the energy storage unit. That is, it optimizes the control command set output by the above system scheduling model based on the current power supply system status (such as the remaining power of the energy storage unit), which reduces the randomness caused by insufficient data accuracy in the prediction stage or the detection error of the remaining power of the energy storage unit or the detected power of the energy storage unit, and further improves the cost optimization or operation benefit optimization effect of the power supply system.

[0007] In one possible implementation, the controller is configured to, if the remaining power of the current energy storage unit is less than the target remaining power, and the grid charging enable indicates that the energy storage unit should receive power from the grid for charging, control the energy storage unit to simultaneously receive power from both the photovoltaic modules and the grid. Here, the controller determines the control strategy for the power converter and energy storage unit for the current control period by combining the control command set corresponding to each control period and the remaining power of the current energy storage unit. That is, it optimizes the control command set output by the above system scheduling model based on the current power supply system state, reducing the randomness caused by insufficient data accuracy in the prediction stage, and further improving the cost optimization or benefit optimization effect of the power supply system.

[0008] In one possible implementation, the controller is configured to: if the remaining power of the current energy storage unit is less than the target remaining power, and the grid charging enable indicates that the energy storage unit should not receive power from the grid for charging, the photovoltaic remaining power allocation indicates that the remaining power of the photovoltaic modules should be prioritized to charge the energy storage unit, and the energy storage unit discharge enable indicates that the energy storage unit is allowed to discharge, control the energy storage unit to only receive power from the photovoltaic modules for charging, control the power converter so that after the load meets the power supply demand, the DC power output by the photovoltaic modules should be prioritized to charge the energy storage unit, and control the power converter to convert the DC power output by the energy storage unit into AC power for output to the load. By combining the control command set corresponding to each control period and the remaining power of the current energy storage unit, the controller determines the control strategy for the power converter and energy storage unit for the current control period. That is, it optimizes the control command set output by the above system scheduling model based on the current power supply system state, reducing the randomness caused by insufficient data accuracy in the prediction stage, and further improving the cost optimization or benefit optimization effect of the power supply system.

[0009] In one possible implementation, the controller is configured to: if the remaining power of the current energy storage unit is less than the target remaining power, and the grid charging enable indicates that the energy storage unit should not receive power from the grid for charging, the photovoltaic remaining power allocation indicates that the remaining power of the photovoltaic module should be prioritized to charge the energy storage unit, and the energy storage unit discharge enable indicates that the energy storage unit should not discharge, then control the energy storage unit to only receive power from the photovoltaic module for charging, and control the power converter so that after the load meets the power supply demand, the DC power output by the photovoltaic module should be prioritized to charge the energy storage unit. The controller determines the control strategy for the power converter and energy storage unit for the current control period by combining the control command set corresponding to each control period and the remaining power of the current energy storage unit. That is, it optimizes the control command set output by the above system scheduling model based on the current power supply system state, reducing the randomness caused by insufficient data accuracy in the prediction stage, and further improving the cost optimization or benefit optimization effect of the power supply system.

[0010] In one possible implementation, the controller is configured to: if the remaining power of the current energy storage unit is less than the target remaining power, and the grid charging enable indicates that the energy storage unit should not receive power from the grid for charging, the photovoltaic remaining power allocation indicates that the remaining power of the photovoltaic modules should be prioritized for grid power supply, and the energy storage unit discharge enable indicates that the energy storage unit is allowed to discharge, control the energy storage unit to only receive power from the photovoltaic modules for charging, control the power converter so that after the load meets the power supply demand, the DC power output by the photovoltaic modules should be prioritized for grid power supply, and control the power converter to convert the DC power output by the energy storage unit into AC power for the load. By combining the control command set corresponding to each control period and the remaining power of the current energy storage unit, the controller determines the control strategy for the power converter and energy storage unit for the current control period. That is, it optimizes the control command set output by the above system scheduling model based on the current power supply system state, reducing the randomness caused by insufficient data accuracy in the prediction stage, and further improving the cost optimization or benefit optimization effect of the power supply system.

[0011] In one possible implementation, the controller is configured to: if the remaining power of the current energy storage unit is less than the target remaining power, and the grid charging enable indicates that the energy storage unit should not receive power from the grid for charging, the photovoltaic remaining power allocation indicates that the remaining power of the photovoltaic modules should be prioritized for grid supply, and the energy storage unit discharge enable indicates that the energy storage unit is allowed to discharge, control the energy storage unit to only receive power from the photovoltaic modules for charging, and control the power converter so that after the load meets the power supply demand, the DC power output by the photovoltaic modules should be prioritized for grid supply. The controller determines the control strategy for the power converter and energy storage unit for the current control period by combining the control command set corresponding to each control period and the remaining power of the current energy storage unit. That is, it optimizes the control command set output by the above system scheduling model based on the current power supply system state, reducing the randomness caused by insufficient data accuracy in the prediction stage, and further improving the cost optimization or benefit optimization effect of the power supply system.

[0012] In one possible implementation, the controller is configured to: if the remaining power of the current energy storage unit is greater than the target remaining power, and the photovoltaic curtailment indicator stops outputting power when the remaining power of the energy storage unit reaches its maximum value and the grid's power supply reaches a power threshold, and the energy storage unit discharge enable indicator allows the energy storage unit to discharge, the controller controls the energy storage unit to only receive power from the photovoltaic module for charging, and controls the power converter to prioritize supplying the grid with the DC power output of the photovoltaic module after the load meets the power demand, and controls the power converter to convert the DC power output of the energy storage unit into AC power for the load. When the photovoltaic curtailment indicator stops outputting power when the remaining power of the energy storage unit reaches its maximum value and the grid's power supply reaches a power threshold, the controller controls the photovoltaic module to prioritize supplying the grid with the DC power output. That is, after the load meets the power demand, the photovoltaic module prioritizes supplying the grid with the DC power output, and the energy storage unit maintains a low remaining power level. This allows the energy storage unit to absorb some power during peak photovoltaic power generation periods, avoiding excessive power waste and improving the power supply efficiency of the power supply system.

[0013] In one possible implementation, the control command set includes a target remaining power, photovoltaic curtailment, and energy storage unit discharge enable. The controller is configured to: if the current remaining power of the energy storage unit is greater than the target remaining power, and the photovoltaic curtailment indicator stops outputting power when the remaining power of the energy storage unit reaches its maximum value and the grid's power supply reaches a power threshold, and the energy storage unit discharge enable indicator disallows the energy storage unit from discharging, control the energy storage unit to only receive power from the photovoltaic module for charging, and control the power converter so that after the load meets the power demand, the DC power output by the photovoltaic module prioritizes power supply to the grid. When the photovoltaic curtailment indicator stops outputting power when the remaining power of the energy storage unit reaches its maximum value and the grid's power supply reaches a power threshold, the controller controls the DC power output by the photovoltaic module to prioritize power supply to the grid. That is, after the load meets the power demand, the DC power output by the photovoltaic module prioritizes power supply to the grid, and the energy storage unit maintains a low remaining power level. This allows the energy storage unit to absorb some power during peak photovoltaic power generation periods, avoiding excessive power waste and improving the power supply efficiency of the power supply system.

[0014] In one possible implementation, the control command set includes target remaining power, photovoltaic curtailment, photovoltaic remaining power allocation, and energy storage unit discharge enable. The controller is configured to: if the current remaining power of the energy storage unit is greater than the target remaining power, and the photovoltaic curtailment instruction indicates that the photovoltaic module continues to output power when the remaining power of the energy storage unit reaches its maximum value and the grid's power supply reaches a power threshold; the photovoltaic remaining power allocation instruction indicates that the remaining power of the photovoltaic module should be prioritized to charge the energy storage unit; the energy storage unit discharge enable instruction indicates that when the energy storage unit is allowed to discharge, control the energy storage unit to only receive power from the photovoltaic module for charging; control the power converter so that after the load meets the power supply demand, the DC power output by the photovoltaic module should be prioritized to charge the energy storage unit; and control the power converter to convert the DC power output by the energy storage unit into AC power for output to the load. The controller determines the control strategy for the power converter and energy storage unit for the current control period by combining the control command set corresponding to each control period and the remaining power of the energy storage unit. That is, it optimizes the control command set output by the above system scheduling model based on the current power supply system status, reduces the randomness caused by insufficient data accuracy in the prediction stage, and further improves the cost optimization or benefit optimization effect of the power supply system.

[0015] In one possible implementation, the control command set includes target remaining power, photovoltaic curtailment, photovoltaic remaining power allocation, and energy storage unit discharge enable. The controller is configured to: if the current remaining power of the energy storage unit is greater than the target remaining power, and the photovoltaic curtailment instruction indicates that the photovoltaic modules continue to output power when the remaining power of the energy storage unit reaches its maximum value and the grid's power supply reaches a power threshold; the photovoltaic remaining power allocation instruction indicates that the remaining power of the photovoltaic modules should be prioritized to charge the energy storage unit; the energy storage unit discharge enable instruction indicates that when the energy storage unit is allowed to discharge, control the energy storage unit to only receive power from the photovoltaic modules for charging; and control the power converter so that after the load meets the power supply demand, the DC power output by the photovoltaic modules should be prioritized to charge the energy storage unit. By combining the control command set corresponding to each control period and the current remaining power of the energy storage unit, the controller determines the control strategy for the power converter and energy storage unit for the current control period. That is, it optimizes the control command set output by the above system scheduling model based on the current power supply system state, reducing the randomness caused by insufficient data accuracy in the prediction stage, and further improving the cost optimization or benefit optimization effect of the power supply system.

[0016] In one possible implementation, the control command set includes target remaining power, photovoltaic curtailment, photovoltaic remaining power allocation, and energy storage unit discharge enable. The controller is configured to: if the current remaining power of the energy storage unit is greater than the target remaining power, and the photovoltaic curtailment indicator allows the photovoltaic modules to continue outputting power when the remaining power of the energy storage unit reaches its maximum value and the grid's power supply reaches a power threshold; the photovoltaic remaining power allocation indicator prioritizes the remaining power of the photovoltaic modules to supply power to the grid; the energy storage unit discharge enable indicator allows the energy storage unit to discharge, controlling the energy storage unit to only receive power from the photovoltaic modules for charging; and controlling the power converter to ensure that the DC power output of the photovoltaic modules prioritizes power supply to the grid after the load meets the power demand. The controller also controls the power converter to convert the DC power output of the energy storage unit into AC power for the load. By combining the control command set corresponding to each control period and the current remaining power of the energy storage unit, the controller determines the control strategy for the power converter and energy storage unit for the current control period. This optimizes the control command set output by the system scheduling model based on the current power supply system state, reducing the randomness caused by insufficient data accuracy in the prediction stage and further improving the cost or benefit optimization effect of the power supply system.

[0017] In one possible implementation, the control command set includes target remaining power, photovoltaic curtailment, photovoltaic remaining power allocation, and energy storage unit discharge enable. The controller is used to: if the current remaining power of the energy storage unit is greater than the target remaining power, and the photovoltaic curtailment instruction indicates that the photovoltaic modules continue to output power when the remaining power of the energy storage unit reaches its maximum value and the grid's power supply reaches a power threshold; if the photovoltaic remaining power allocation instruction indicates that the remaining power of the photovoltaic modules should be prioritized for grid supply; if the energy storage unit discharge enable instruction indicates that the energy storage unit is not allowed to discharge, control the energy storage unit to only receive power from the photovoltaic modules for charging; and control the power converter so that after the load meets the power supply demand, the DC power output by the photovoltaic modules should be prioritized for grid supply. By combining the control command set corresponding to each control period and the current remaining power of the energy storage unit, the controller determines the control strategy for the power converter and energy storage unit for the current control period. That is, it optimizes the control command set output by the above system scheduling model based on the current power supply system state, reducing the randomness caused by insufficient data accuracy in the prediction stage, and further improving the cost optimization or benefit optimization effect of the power supply system.

[0018] In one possible implementation, the controller acquires the load power consumption, photovoltaic module power generation, and grid electricity price at preset time intervals. Based on the acquired load power consumption, photovoltaic module power generation, and grid electricity price, it updates the load power consumption, photovoltaic module power generation, and grid electricity price input to the photovoltaic-storage system scheduling model, thereby obtaining an updated set of control commands through the system scheduling model. By combining the control command set corresponding to each control period and the remaining power of the energy storage unit, the controller determines the control strategy for the power converter and energy storage unit for the current control period. That is, it optimizes the control command set output by the system scheduling model based on the current power supply system state, reducing the randomness caused by insufficient data accuracy in the prediction stage, and further improving the cost optimization or revenue optimization effect of the power supply system. Attached Figure Description

[0019] Figure 1 is a schematic diagram of an application scenario of the power supply system provided in this application;

[0020] Figure 2 is a schematic diagram of another application scenario of the power supply system provided in this application;

[0021] Figure 3 is a schematic diagram of another application scenario of the power supply system provided in this application;

[0022] Figure 4 is a schematic diagram of energy dispatch control of the power supply system provided in this application;

[0023] Figure 5 is a schematic diagram of the generation of the control instruction set provided in this application;

[0024] Figure 6 is a schematic diagram of the composition of the control instructions provided in this application;

[0025] Figure 7 is a schematic diagram of the control strategy selection process provided in this application. Detailed Implementation

[0026] Referring to Figure 1, which is a schematic diagram of an application scenario of the power supply system provided in this application, the power supply system provided in this application may include a DC power supply, a power converter, and a backup power device. The DC power supply may be a photovoltaic array, which consists of multiple photovoltaic modules connected in series or parallel. The output terminal of the photovoltaic module can be connected to one end of the power converter, and the other end of the power converter is connected to the load and the power grid. The power converter inverts and converts the DC power provided by the photovoltaic module, and outputs the converted AC power to the load or the power grid. Alternatively, the load may also draw power from the power grid. The load may be AC ​​electrical equipment such as household appliances.

[0027] Referring again to Figure 1, the DC power supply may also include an energy storage unit, which can be an energy storage battery. The output terminal of the energy storage battery can be connected to one end of a power converter. The power converter can invert and convert the DC power provided by the energy storage battery, and output the converted AC power to the load. Alternatively, the aforementioned energy storage battery can be charged by receiving DC power provided by photovoltaic modules, or it can be charged by receiving DC power after the power converter rectifies the AC power from the grid.

[0028] In some feasible implementations, the power converter described above may include a DC-DC converter circuit and an inverter circuit. Referring to Figure 2, which is a schematic diagram of another application scenario of the power supply system provided in this application, the power converter includes a DC-DC converter circuit and an inverter circuit. The input terminal of the DC-DC converter circuit can be connected to the photovoltaic module, and the output terminal of the DC-DC converter circuit can be connected to the input terminal of the inverter circuit. The output terminal of the inverter circuit is used to connect the load and the power grid. Here, the power converter can transform the DC power provided by the photovoltaic array through the DC-DC converter circuit, and then invert and convert the transformed DC power through the inverter circuit. The AC power obtained after the inversion and conversion is used to supply power to the load or the power grid.

[0029] Referring again to Figure 2, the DC power supply may also include an energy storage battery. The output of the energy storage battery can be connected to the output of the DC-DC conversion circuit in the power converter described above. The energy storage battery can provide DC power to the inverter circuit described above. The inverter circuit converts the DC power provided by the energy storage battery into AC power and outputs it to the load. Alternatively, the DC power provided by the photovoltaic array in Figure 2 can be transformed by the DC-DC conversion circuit in the power converter, and the energy storage battery can receive the DC power output from the power converter for charging.

[0030] Optionally, the photovoltaic module and the energy storage battery can each be connected to a power converter. Referring to Figure 3, which is a schematic diagram of another application scenario of the power supply system provided in this application, as shown in Figure 3, the output terminals of the photovoltaic module and the energy storage battery can each be connected to one end of a power converter, and the other end of each power converter is connected to the load and the power grid. The power converter connected to the photovoltaic module can be an inverter, and the power converter connected to the energy storage battery can be an energy storage converter.

[0031] In the application scenario shown in Figure 1, efficient management and optimized scheduling of power supply system energy are crucial. Power supply system energy management includes the energy output of each photovoltaic module and the energy input and output of energy storage units. Typically, energy management involves real-time monitoring and forecasting of multiple aspects such as photovoltaic power generation, energy storage systems, and load demand, as well as the formulation and implementation of energy scheduling strategies based on this data. The complexity and real-time requirements of the energy management process increase the difficulty of technical implementation. How to formulate reasonable economic optimization models and algorithms to minimize the operating costs and maximize the benefits of the power supply system is a challenging technical problem. However, for photovoltaic-storage-load microgrid power supply systems in residential, industrial, and commercial scenarios, due to factors such as small load scale, high randomness, and inferior public grid signal quality compared to dedicated power grids, the control accuracy and cost optimization effects of traditional centralized large power grids or regional power grids cannot meet the requirements.

[0032] The power supply system provided in this application includes a power converter and a controller. The power converter converts the direct current (DC) output from photovoltaic (PV) modules and / or energy storage units into alternating current (AC) output to the load or the power grid. Specifically, the controller acquires the load power consumption, PV module power generation, PV feed-in tariff, and grid electricity price within a set control interval. It then inputs these data into a PV-storage system scheduling model, which generates a set of control commands for multiple control periods within the set control interval. The system scheduling model combines predicted or configured data such as load power consumption, PV module power generation, PV feed-in tariff, and grid electricity price. Using the minimization of power supply system operating costs or maximization of revenue as the objective function, and considering grid electricity price, PV-storage configuration, and constraints, the model models and solves for the optimal control scheme within the set control interval, thus obtaining the set of control commands for multiple control periods within the set control interval. This set of control commands may include target remaining power, grid charging enable, PV remaining power allocation, energy storage unit discharge enable, and PV curtailment. Under the control of the control command set corresponding to any control period, the power converter and energy storage unit minimize the operating cost or maximize the benefit of the power supply system during that control period. In other words, when the power converter and energy storage unit are controlled by the control command set corresponding to each control period, the operating cost of the power supply system in each control period is the target cost or the operating benefit is the target benefit. Furthermore, the controller is used to determine the control strategy based on the control command set corresponding to each control period and the remaining power of the energy storage unit, and to control the power converter and energy storage unit based on the control strategy. Here, the controller determines the control strategy for the power converter and energy storage unit for the current control period by combining the control command set corresponding to each control period and the remaining power of the energy storage unit. That is, it optimizes the control command set output by the system scheduling model based on the current power supply system state (e.g., the remaining power of the energy storage unit), reducing the randomness caused by insufficient data accuracy in the prediction stage or detection errors in the remaining power or detected power of the energy storage unit, further improving the cost optimization or operating benefit optimization effect of the power supply system.

[0033] Referring to Figure 4, which is a schematic diagram of the energy dispatch control of the power supply system provided in this application, the energy dispatch control of the power supply system includes three levels: Level A, Level B, and Level C. These levels can be implemented by different controllers or by the same controller. Level A includes a data prediction unit and a modeling and solving unit. In the data prediction part, the controller can obtain predicted data such as load power consumption, photovoltaic module power generation, photovoltaic feed-in tariff, and grid electricity price within a set control interval, for example, from the present to the next 24 hours. In the modeling and solving part, the controller can input the predicted load power consumption, photovoltaic module power generation, photovoltaic feed-in tariff, and grid electricity price into the photovoltaic-storage system dispatch model, and obtain a set of control commands corresponding to multiple control periods within the set control interval through the system dispatch model. The aforementioned system scheduling model combines predicted data such as load power consumption, photovoltaic module power generation, photovoltaic feed-in tariff, and grid electricity price. Using the minimization of power supply system operating costs or the maximization of operating revenue as the objective function, and considering grid electricity price, photovoltaic-storage configuration, and constraints, it models and solves for the optimal control scheme within a defined control interval. This yields a set of control instructions for multiple control periods within the defined control interval, which is then output to layer B. Layer B generates the final control strategy based on the received control instructions. Layer C, based on the control strategy, controls the power converter and energy storage unit through local control modules, optimizing the overall operating costs or operating revenue of the power supply system while meeting load demands.

[0034] Optionally, during the energy dispatch control process of the aforementioned power supply system, the controller can periodically update the control instruction set and periodically send the updated control instruction set to level B. Please refer to Figure 5, which is a schematic diagram of the control instruction set generation provided in this application. As shown in Figure 5, the controller inputs the predicted data obtained from the system dispatch model. This predicted data is the predicted data within the control interval T1 to Tn, and obtains the control instruction set within the control interval T1 to Tn through the photovoltaic-storage system dispatch model. The control interval T1 to Tn includes n control periods: T1, T2, ..., Tn. The control instruction set within the control interval T1 to Tn includes "C1_1, C1_2, ..., C1_n". "C1_1" includes the control instruction set corresponding to control period T1, "C1_2" includes the control instruction set corresponding to control period T2, and so on. The control instruction set within the control interval T1 to Tn can be sent to level B, enabling level B to generate a control strategy based on the received control instruction set. For example, during control period T1, layer B generates a control strategy applicable to control period T1 based on the control instruction set C1_1; during control period T2, layer B generates a control strategy applicable to control period T2 based on the control instruction set C1_2, and so on. Here, the controller obtains a set of control instructions for a control interval each time through the photovoltaic-storage system scheduling model, thus obtaining a set of control instructions corresponding to multiple control periods within a control interval. This ensures the generation and implementation of control strategies within the control interval, resulting in high control reliability of the power supply system.

[0035] Furthermore, the controller can acquire the load power consumption, photovoltaic module power generation, and grid electricity price at preset time intervals. Based on the acquired load power consumption, photovoltaic module power generation, photovoltaic grid-connected electricity price, and grid electricity price, it updates the load power consumption, photovoltaic module power generation, photovoltaic grid-connected electricity price, and grid electricity price input to the photovoltaic-storage system scheduling model, so as to obtain an updated set of control commands through the aforementioned system scheduling model. For example, referring again to Figure 5 above, the control interval T1 to Tn in Figure 5 can be 24 hours, that is, the control interval includes 24 control periods, and the control periods T1, T2, ..., T24 included in the control interval correspond to the 1st hour, the 2nd hour, ..., the 24th hour, respectively. The aforementioned preset time interval can be 1 hour, half an hour, or 15 minutes, etc. Taking a preset time interval of 1 hour as an example, after 1 hour, the control interval is updated from T1 to Tn to T2 to Tn+1. The controller obtains the predicted data within T2 to Tn+1, namely, the load power consumption, photovoltaic module power generation, photovoltaic feed-in tariff, and grid electricity price within T2 to Tn+1, and inputs them into the system scheduling model. The photovoltaic-storage system scheduling model obtains the corresponding set of control commands within the control interval T2 to Tn+1. The set of control commands within the aforementioned control interval T2 to Tn+1 includes "C2_2, C2_3, ..., C2_n+1". Among them, "C2_2" is the set of control commands corresponding to the second generated control period T2, "C2_3" is the set of control commands corresponding to the second generated control period T3, and so on. Similarly, after one hour, the control interval is updated from T2 to Tn+1 to T3 to Tn+2. The controller re-acquires the predicted data within the control interval T3 to Tn+2 and inputs it into the system scheduling model. The photovoltaic-storage system scheduling model then obtains the set of control commands within the control interval T3 to Tn+2. This set of control commands includes "C3_3, C3_4, ..., C3_n+2". The control command set within the control interval T3 to Tn+2, as well as the control command sets updated in subsequent control intervals, are described in the previous sections on the control command sets for control intervals T2 to Tn and T2 to Tn+1, and will not be repeated here. Understandably, the controller periodically sends the updated set of control commands to layer B. For example, the control command set within the control interval T2 to Tn+1 can be sent to layer B, allowing layer B to generate control strategies applicable to each control period based on the received set of control commands. Here, the controller updates the set of control instructions, which can avoid the limitations of the predicted data from affecting the final strategy selection, further optimize the control accuracy of the energy dispatch strategy, and improve the cost optimization or benefit optimization effect.

[0036] In some feasible implementations, the control command set includes target remaining power, grid charging enable, energy storage unit discharge enable, photovoltaic remaining power allocation, and photovoltaic curtailment. Taking the control command set within the control interval T1 to Tn shown in Figure 5 as an example, the control interval T1 to Tn can be 24 hours, that is, the control interval includes 24 control periods. The control periods T1, T2, ..., T24 included in the control interval correspond to the 1st hour, the 2nd hour, ..., the 24th hour, respectively, and the control periods T1, T2, ..., T24 correspond to the control command sets "C1_1", "C1_2", ..., "C1_24", respectively. Please also refer to Figure 6, which is a schematic diagram of the composition of the control commands provided in this application. As shown in Figure 6, the control command set corresponding to each control period includes target remaining power, grid charging enable, energy storage unit discharge enable, photovoltaic remaining power allocation, and photovoltaic curtailment. Among them, the above-mentioned grid charging enable includes instructing the energy storage unit in the power supply system to receive power supplied by the grid for charging, or instructing the energy storage unit not to receive power supplied by the grid for charging. The aforementioned allocation of surplus photovoltaic (PV) power includes instructing the PV modules in the power supply system to prioritize charging the energy storage unit, or instructing the PV modules to prioritize supplying power to the grid. The surplus power of the PV modules refers to the power that the PV modules do not output after the load meets the power supply demand. The aforementioned enabling of energy storage unit discharge includes instructing the energy storage unit to discharge, or instructing the energy storage unit not to discharge. The aforementioned curtailment of PV power includes instructing the PV modules to stop outputting power when the remaining power of the energy storage unit reaches its maximum value and the grid's power supply reaches a power threshold, or instructing the PV modules to continue outputting power when the remaining power of the energy storage unit reaches its maximum value and the grid's power supply reaches a power threshold. Here, "1" and "0" can be used to represent the different instructions corresponding to grid charging enable, energy storage unit discharge enable, PV surplus power allocation, and PV curtailment, or "true" and "false" or other different pairs of identifiers can be used to distinguish different instructions; no restrictions are imposed here. Taking the distinction between different instructions using "1" and "0" as an example, as shown in Figure 6, when the grid charging enable is 1, it instructs the energy storage unit in the power supply system to receive power from the grid for charging; when the grid charging enable is 0, it instructs the energy storage unit not to receive power from the grid for charging. Similarly, when the photovoltaic surplus energy allocation is 1, it instructs the surplus energy of the photovoltaic modules in the power supply system to prioritize charging the energy storage unit; when the photovoltaic surplus energy allocation is 0, it instructs the surplus energy of the photovoltaic modules to prioritize supplying power to the grid. Finally, when the energy storage unit discharge enable is 1, it instructs that the energy storage unit is allowed to discharge; when the energy storage unit discharge enable is 0, it instructs that the energy storage unit is not allowed to discharge.When the aforementioned photovoltaic curtailment is 1, it indicates that the photovoltaic modules will stop outputting power when the remaining power of the energy storage unit reaches its maximum value and the grid's power supply reaches the power threshold. When the photovoltaic curtailment is 0, it indicates that the photovoltaic modules will continue outputting power when the remaining power of the energy storage unit reaches its maximum value and the grid's power supply reaches the power threshold. Here, the aforementioned photovoltaic modules can provide power when the load's power demand is met, the energy storage unit is fully charged (i.e., the remaining power reaches its maximum value), and the grid's power supply reaches the power threshold; and stop outputting power when the remaining power of the energy storage unit reaches its maximum value and the grid's power supply reaches the power threshold. The controller can determine the control strategy based on the control command set corresponding to each control period and the current remaining power of the energy storage unit, and control the power converter and energy storage unit based on the control strategy. For example, in the control instruction set C1_1 corresponding to the control period T1, i.e. the first hour, the values ​​of target remaining power, grid charging enable, energy storage unit discharge enable, photovoltaic remaining power allocation, and photovoltaic curtailment are 50%, 1, 0, 0, and 0, respectively. The controller can determine the control strategy in the first hour based on the instructions in instruction set C1_1 and the current remaining power of the energy storage unit, and control the power converter and energy storage unit based on the control strategy.

[0037] In some feasible implementations, the controller is used to determine a control strategy based on the set of control instructions corresponding to each control period and the remaining power of the current energy storage unit, and to control the power converter and energy storage unit based on the control strategy. Referring again to Figure 4, layer B generates the final control strategy based on the received set of control instructions, so that layer C controls the power converter and energy storage unit through the local control module based on the received control strategy. Specifically, layer C can receive the control strategy at certain time intervals, such as receiving the control strategy issued by layer B every minute. Then, layer C, through the local control module, combines the control strategy with the current power supply system status, load power consumption, photovoltaic module power generation, and other boundary constraints to perform real-time active power and reactive power allocation. The local control module performs millisecond-level or second-level closed-loop control of the power converter and energy storage unit of the power supply system based on the given target active power and target reactive power values. Further, layer B includes a remaining power tracking unit, a control strategy set unit, and a system status unit. The system status unit provides the remaining power tracking unit with the current power supply system status, such as the remaining power of the current energy storage unit. The remaining power tracking unit combines the remaining power of the current energy storage unit with the control command set corresponding to the current control period to determine the control strategy from the control strategy set unit and issue it to level C. See Figure 7, which is a schematic diagram of the control strategy selection process provided in this application. As shown in Figure 7, taking "1" and "0" to distinguish different commands as an example, "1" is used when the remaining power of the current energy storage unit (which can be represented as the current SOC) is less than the target remaining power (which can be represented as the target SOC) in the control command set, and "0" is used when the current SOC is greater than the target SOC. The control strategy can include "charging window", "discharging window - grid connection priority", "non-charging / non-discharging window - grid connection priority", "discharging window - charging priority", "non-charging / non-discharging window - charging priority", "discharging window - grid connection priority - curtailment", and "non-charging / non-discharging window - grid connection priority - curtailment".

[0038] The controller combines the remaining power of the current energy storage unit with the control command set corresponding to the current control period to determine the final control strategy. For example, taking the control command set shown in Figure 6 as an example, in the control period corresponding to the first hour, if the remaining power of the current energy storage unit is 40%, it is determined that the current SOC is less than the target SOC, and the grid charging enable in the command set C1_1 is 1. Then the control strategy is determined to be "charging window". In the "charging window", the controller controls the energy storage unit to receive power from both the photovoltaic module and the grid for charging. Next, during the control period corresponding to the second hour, in the control instruction set C1_2, if the remaining power of the energy storage unit is 55%, it is determined that the current SOC is less than the target SOC. Furthermore, in instruction set C1_2, the grid charging enable is 0, the photovoltaic remaining power allocation is 0, and the energy storage unit discharge enable is 1. Therefore, the control strategy is determined to be "discharge window - grid connection priority." In "discharge window - grid connection priority," the controller controls the energy storage unit to only receive power from the photovoltaic modules for charging. It controls the power converter so that after the load meets the power demand, the DC power output from the photovoltaic modules prioritizes supplying power to the grid. It also controls the power converter to convert the DC power output from the energy storage unit into AC power for the load. It is understandable that in the control period corresponding to the third hour and subsequent control periods, the process of the controller determining the control strategy based on the control instruction set corresponding to each control period and the remaining power of the current energy storage unit is similar to that of the control periods corresponding to the first and second hours.

[0039] Referring again to Figure 7, if the current SOC is less than the target SOC, and the grid charging enable, photovoltaic surplus energy allocation, and energy storage unit discharge enable are all set to 0 in the instruction set; or if the current SOC is greater than the target SOC, and the photovoltaic curtailment, photovoltaic surplus energy allocation, and energy storage unit discharge enable are all set to 1 in the instruction set, then the control strategy is determined to be "discharge window - grid connection priority". Specifically, in "discharge window - grid connection priority", the controller controls the energy storage unit to only receive electrical energy provided by the photovoltaic modules for charging, controls the power converter to ensure that after the load meets the power supply demand, the DC power output by the photovoltaic modules is prioritized to supply power to the grid, and controls the power converter to convert the DC power output by the energy storage unit into AC power for output to the load. If the current SOC is less than the target SOC, and the grid charging enable, photovoltaic surplus power allocation, and energy storage unit discharge enable are all set to 0 in the instruction set; or if the current SOC is greater than the target SOC, and the photovoltaic curtailment, photovoltaic surplus power allocation, and energy storage unit discharge enable are all set to 0 in the instruction set, then the control strategy is determined to be "non-charging and non-discharging window - grid connection priority". In the "non-charging and non-discharging window - grid connection priority" mode, the controller controls the energy storage unit to only receive power from the photovoltaic modules for charging, and controls the power converter so that after the load meets the power supply demand, the DC power output by the photovoltaic modules is prioritized to supply power to the grid. If the current SOC is less than the target SOC, and the grid charging enable is 0, the photovoltaic surplus power allocation is 1, and the energy storage unit discharge enable is 1 in the instruction set; or if the current SOC is greater than the target SOC, and the photovoltaic curtailment is 0, the photovoltaic surplus power allocation is 1, and the energy storage unit discharge enable is 1 in the instruction set, then the control strategy is determined to be "discharge window - charging priority". In "discharge window - charging priority", the controller controls the power converter so that after the load meets the power supply demand, the DC power output by the photovoltaic module is prioritized to charge the energy storage unit, and the controller controls the power converter to convert the DC power output by the energy storage unit into AC power to be output to the load. If the current SOC is less than the target SOC, and the grid charging enable, photovoltaic surplus power allocation, and energy storage unit discharge enable are all set to 0 in the instruction set, or if the current SOC is greater than the target SOC, and the photovoltaic curtailment is all set to 0 in the instruction set, photovoltaic surplus power allocation, and energy storage unit discharge enable are all set to 0, then the control strategy is determined to be "non-charging and non-discharging window - charging priority". In the "non-charging and non-discharging window - charging priority" mode, the controller controls the energy storage unit to only receive power from the photovoltaic modules for charging, and controls the power converter so that after the load meets the power supply requirements, the DC power output by the photovoltaic modules is prioritized to charge the energy storage unit.If the current SOC is greater than the target SOC, and the photovoltaic curtailment setting in the instruction set is 1 and the energy storage unit discharge enable setting is 1, then the control strategy is determined to be "discharge window - grid connection priority - curtailment". In "discharge window - grid connection priority - curtailment", the controller controls the power converter to prioritize supplying the grid with the DC power output of the photovoltaic modules after the load meets the power demand. The controller also controls the power converter to convert the DC power output of the energy storage unit into AC power for the load. Furthermore, the photovoltaic modules are used to stop outputting power when the remaining capacity of the energy storage unit reaches its maximum value and the grid's power supply reaches a power threshold. If the current SOC is greater than the target SOC, and the photovoltaic curtailment setting in the instruction set is 1 and the energy storage unit discharge enable setting is 0, then the control strategy is determined to be "non-charge / non-discharge window - grid connection priority - curtailment". In "non-charge / non-discharge window - grid connection priority - curtailment", the controller controls the power converter to prioritize supplying the grid with the DC power output of the photovoltaic modules after the load meets the power demand. Furthermore, the photovoltaic modules are used to stop outputting power when the remaining power of the energy storage unit reaches its maximum value and the grid's power supply reaches a power threshold. Here, the controller determines the control strategy for the power converter and energy storage unit for the current control period by combining the control command set corresponding to each control period and the current remaining power of the energy storage unit. That is, it optimizes the control command set output by the above system scheduling model based on the current power supply system status (such as the remaining power of the energy storage unit), reducing the randomness caused by insufficient data accuracy in the prediction stage, and further improving the cost optimization or benefit optimization effect of the power supply system. In addition, in the control scenario where the photovoltaic modules are instructed to stop outputting power when the remaining power of the energy storage unit reaches its maximum value and the grid's power supply reaches a power threshold, the DC power output by the photovoltaic modules is controlled to prioritize powering the grid. That is, after the load meets the power supply demand, the DC power output by the photovoltaic modules is prioritized to power the grid, and the energy storage unit maintains a low remaining power level. This allows the energy storage unit to absorb some power during the peak power generation period of the photovoltaic modules, avoiding the waste of too much power and improving the power supply efficiency of the power supply system.

Claims

1. A power supply system, characterized in that, The power supply system includes a power converter and a controller. The power converter is used to convert the direct current output from the photovoltaic modules and / or energy storage units into alternating current output to the load or the power grid. The controller is used to determine the target remaining power, grid charging enablement, photovoltaic remaining power allocation, energy storage unit discharge enablement, photovoltaic curtailment, and the current remaining power of the energy storage unit. The energy storage unit can be controlled to receive power from both the photovoltaic module and the power grid for charging, or the energy storage unit can be controlled to receive power from only the photovoltaic module for charging. The power converter is controlled so that after the load meets the power supply demand, the remaining power of the photovoltaic module is preferentially used to charge the energy storage unit or preferentially to supply power to the grid. The power converter is controlled to convert the DC power output from the energy storage unit into AC power and output it to the load, or the energy storage unit is controlled not to discharge. The photovoltaic module can be controlled to stop outputting electrical energy or continue outputting electrical energy when the remaining power of the energy storage unit reaches its maximum value and the power supply of the power grid reaches a power threshold.

2. The power supply system according to claim 1, characterized in that, The controller is configured to, if the remaining power of the current energy storage unit is less than the target remaining power, and the grid charging enable instructs the energy storage unit to receive power from the grid for charging, The energy storage unit is controlled to simultaneously receive electrical energy from the photovoltaic module and the power grid for charging.

3. The power supply system according to claim 1, characterized in that, The controller is configured to: if the remaining power of the current energy storage unit is less than the target remaining power, and the grid charging enable indicates that the energy storage unit should not receive power from the grid for charging, the photovoltaic remaining power allocation indicates that the remaining power of the photovoltaic module should be prioritized to charge the energy storage unit, and the energy storage unit discharge enable indicates that the energy storage unit is allowed to discharge. The energy storage unit is controlled to receive only the electrical energy provided by the photovoltaic module for charging. The power converter is controlled so that after the load meets the power supply requirements, the DC power output by the photovoltaic module is preferentially used to charge the energy storage unit. The power converter is controlled to convert the DC power output by the energy storage unit into AC power and output it to the load.

4. The power supply system according to claim 1, characterized in that, The controller is configured to: if the remaining power of the current energy storage unit is less than the target remaining power, and the grid charging enable indicates that the energy storage unit should not receive power from the grid for charging, the photovoltaic remaining power allocation indicates that the remaining power of the photovoltaic module should be prioritized to charge the energy storage unit, and the energy storage unit discharge enable indicates that the energy storage unit should not discharge; The energy storage unit is controlled to receive only the electrical energy provided by the photovoltaic module for charging, and the power converter is controlled so that after the load meets the power supply requirements, the DC power output by the photovoltaic module is preferentially used to charge the energy storage unit.

5. The power supply system according to claim 1, characterized in that, The controller is configured to: if the remaining power of the current energy storage unit is less than the target remaining power, and the grid charging enable indicates that the energy storage unit will not receive power from the grid for charging, the photovoltaic remaining power allocation indicates that the remaining power of the photovoltaic module will be prioritized for power supply to the grid, and the energy storage unit discharge enable indicates that the energy storage unit is allowed to discharge; The energy storage unit is controlled to receive only the electrical energy provided by the photovoltaic module for charging. The power converter is controlled so that after the load meets the power supply requirements, the DC power output by the photovoltaic module is prioritized to supply the grid. The power converter is controlled to convert the DC power output by the energy storage unit into AC power and output it to the load.

6. The power supply system according to claim 1, characterized in that, The controller is configured to: if the remaining power of the current energy storage unit is less than the target remaining power, and the grid charging enable indicates that the energy storage unit will not receive power from the grid for charging, the photovoltaic remaining power allocation indicates that the remaining power of the photovoltaic module will be prioritized for power supply to the grid, and the energy storage unit discharge enable indicates that the energy storage unit is allowed to discharge; The energy storage unit is controlled to receive only the electrical energy provided by the photovoltaic module for charging, and the power converter is controlled so that after the load meets the power supply requirements, the DC power output by the photovoltaic module is preferentially supplied to the power grid.

7. The power supply system according to claim 1, characterized in that, The controller is configured to, if the remaining power of the current energy storage unit is greater than the target remaining power, and the photovoltaic curtailment indicator indicates that the photovoltaic module stops outputting power when the remaining power of the energy storage unit reaches its maximum value and the power supply of the grid reaches a power threshold, and the energy storage unit discharge enable indicator allows the energy storage unit to discharge. The energy storage unit is controlled to receive only the electrical energy provided by the photovoltaic module for charging. The power converter is controlled so that after the load meets the power supply requirements, the DC power output by the photovoltaic module is prioritized to supply the grid. The power converter is controlled to convert the DC power output by the energy storage unit into AC power and output it to the load.

8. The power supply system according to claim 1, characterized in that, The controller is configured to, if the remaining power of the current energy storage unit is greater than the target remaining power, and the photovoltaic curtailment indicator indicates that the photovoltaic module stops outputting power when the remaining power of the energy storage unit reaches its maximum value and the power supply of the grid reaches a power threshold, and the energy storage unit discharge enable indicator indicates that the energy storage unit is not allowed to discharge, The energy storage unit is controlled to receive only the electrical energy provided by the photovoltaic module for charging, and the power converter is controlled so that after the load meets the power supply requirements, the DC power output by the photovoltaic module is preferentially supplied to the power grid.

9. The power supply system according to claim 1, characterized in that, The controller is configured to: if the remaining power of the current energy storage unit is greater than the target remaining power, and the photovoltaic curtailment indicator indicates that the photovoltaic module continues to output power when the remaining power of the energy storage unit reaches its maximum value and the power supply of the grid reaches a power threshold; the photovoltaic remaining power allocation indicator indicates that the remaining power of the photovoltaic module should be preferentially used to charge the energy storage unit; and the energy storage unit discharge enable indicator indicates that the energy storage unit is allowed to discharge. The energy storage unit is controlled to receive only the electrical energy provided by the photovoltaic module for charging. The power converter is controlled so that after the load meets the power supply requirements, the DC power output by the photovoltaic module is preferentially used to charge the energy storage unit. The power converter is controlled to convert the DC power output by the energy storage unit into AC power and output it to the load.

10. The power supply system according to claim 1, characterized in that, The controller is configured to: if the remaining power of the current energy storage unit is greater than the target remaining power, and the photovoltaic curtailment instruction indicates that the photovoltaic module continues to output power when the remaining power of the energy storage unit reaches its maximum value and the power supply of the grid reaches a power threshold; the photovoltaic remaining power allocation instruction indicates that the remaining power of the photovoltaic module should be preferentially used to charge the energy storage unit; and the energy storage unit discharge enable instruction indicates that the energy storage unit is allowed to discharge. The energy storage unit is controlled to receive only the electrical energy provided by the photovoltaic module for charging, and the power converter is controlled so that after the load meets the power supply requirements, the DC power output by the photovoltaic module is preferentially used to charge the energy storage unit.

11. The power supply system according to claim 1, characterized in that, The controller is configured to: if the remaining power of the current energy storage unit is greater than the target remaining power, and the photovoltaic curtailment indicator allows the photovoltaic module to continue outputting power when the remaining power of the energy storage unit reaches its maximum value and the power supply of the grid reaches a power threshold; the photovoltaic remaining power allocation indicator prioritizes the remaining power of the photovoltaic module to supply power to the grid; and the energy storage unit discharge enable indicator allows the energy storage unit to discharge. The energy storage unit is controlled to receive only the electrical energy provided by the photovoltaic module for charging. The power converter is controlled so that after the load meets the power supply requirements, the DC power output by the photovoltaic module is prioritized to supply the grid. The power converter is controlled to convert the DC power output by the energy storage unit into AC power and output it to the load.

12. The power supply system according to claim 1, characterized in that, The controller is configured to: if the remaining power of the current energy storage unit is greater than the target remaining power, and the photovoltaic curtailment indicator indicates that the photovoltaic module continues to output power when the remaining power of the energy storage unit reaches its maximum value and the power supply of the grid reaches a power threshold; the photovoltaic remaining power allocation indicator indicates that the remaining power of the photovoltaic module should be prioritized to supply power to the grid; and the energy storage unit discharge enable indicator indicates that the energy storage unit is not allowed to discharge. The energy storage unit is controlled to receive only the electrical energy provided by the photovoltaic module for charging, and the power converter is controlled so that after the load meets the power supply requirements, the DC power output by the photovoltaic module is preferentially supplied to the power grid.

13. The power supply system according to any one of claims 1-12, characterized in that, The controller is used to acquire the load power consumption of the load, the power generation of the photovoltaic module, and the electricity price of the grid once every preset time interval, and to obtain the target remaining power, grid charging enable, photovoltaic remaining power allocation, energy storage unit discharge enable, and photovoltaic curtailment based on the acquired load power consumption, photovoltaic power generation, and electricity price of the grid.

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