Method for optimizing energy storage charging and discharging strategy based on sensitivity

Abstract

The invention provides a method for optimizing an energy storage charging and discharging strategy based on sensitivity, and relates to the technical field of power system energy storage, and the method comprises the steps: obtaining current section power flow data and a current section power flow limit value, and judging whether a current heavy load / out-of-limit section exists or not according to a preset heavy load / out-of-limit standard; an energy storage charging and discharging request is received, energy storage section sensitivity is obtained, and whether energy storage charging and discharging operation is allowed or not is determined by combining a judgment result; if the energy storage charging and discharging operation is allowed, the charging and discharging maximum power is calculated; constructing a short-term load prediction model to determine predicted section power flow data; constructing an energy storage charging and discharging strategy to calculate a predicted section power flow variable quantity, and combining the predicted section power flow data to obtain simulated section power flow data; judging whether a future heavy load / out-of-limit section exists according to a preset heavy load / out-of-limit standard, and adjusting an energy storage charging and discharging strategy, thereby improving the real-time performance and adaptability of energy storage charging and discharging, improving the energy storage utilization efficiency, and guaranteeing the safe operation of a power grid.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage in power systems, and particularly to a method for optimizing energy storage charge and discharge strategies based on sensitivity. Background Art

[0002] Currently, when arranging energy storage charge and discharge plans, it is necessary to consider their impact on the line and main transformer power flow to avoid aggravating the power flow over-limit situation of the main transformer or line during the charge and discharge process.

[0003] At present, the arrangement of energy storage charge and discharge plans often depends on the dispatcher's understanding of the grid operation. However, during the grid operation, the power flow change is restricted by various factors, and the power flow calculation amount changes exponentially with the change of the grid network structure and the increase of the grid complexity. Manual calculation not only has a large workload but also consumes a lot of time. In this mode, it is difficult for the dispatcher to determine whether the current energy storage charge and discharge plan will aggravate the section over-limit situation or cause a new over-limit section to appear, nor can it determine the maximum power of the current energy storage charge and discharge. At the same time, the dispatcher can only optimize the energy storage charge and discharge time based on the current section and power flow conditions. When the grid changes within the next four hours, it cannot adjust the energy storage charge and discharge plan in time.

[0004] Therefore, it is necessary to provide a method for optimizing energy storage charge and discharge strategies based on sensitivity to solve the above technical problems. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a method for optimizing energy storage charge and discharge strategies based on sensitivity, which is used to solve the problems that the current energy storage charge and discharge plan depends on manual scheduling, has insufficient real-time performance, poor dynamic adaptability, high computational complexity and low efficiency.

[0006] The method for optimizing energy storage charge and discharge strategies based on sensitivity provided by the present invention includes: Obtain the current section power flow data and the current section power flow limit value, and judge whether there is a current heavy load / over-limit section according to the preset heavy load / over-limit standard; Receive the energy storage charge and discharge request, obtain the energy storage section sensitivity, and determine whether to allow the energy storage charge and discharge operation in combination with the judgment result of the current heavy load / over-limit section; If the energy storage charge and discharge operation is allowed, calculate the maximum power of the energy storage charge and discharge based on the current section power flow data and the current section power flow limit value; Construct a short-term load prediction model, and determine the predicted section power flow data according to the current section power flow data; Construct an energy storage charge and discharge strategy based on the maximum power of the energy storage charge and discharge, calculate the change amount of the predicted section power flow, and obtain the simulated section power flow data in combination with the predicted section power flow data; Based on the simulated cross-section tidal current data, determine whether there is a future overloaded / overlimit cross-section according to the preset overloaded / overlimit standard, and adjust the energy storage charge and discharge strategy.

[0007] Preferably, the method for obtaining the current cross-section tidal current data and the current cross-section tidal current limit value, and determining whether there is a current overloaded / overlimit cross-section according to the preset overloaded / overlimit standard specifically includes: Based on the data acquisition and monitoring control system, collect the current cross-section tidal current data and the current cross-section tidal current limit value in real time; Based on the preset overloaded / overlimit standard, determine whether there is the current overloaded / overlimit cross-section according to the current cross-section tidal current data and the current cross-section tidal current limit value. The corresponding calculation formula is as follows: In the formula, PDJG represents the judgment result of the current overloaded / overlimit cross-section; represents the current cross-section tidal current data; represents the current cross-section tidal current limit value.

[0008] Preferably, the method for receiving the energy storage charge and discharge request, obtaining the energy storage cross-section sensitivity, and determining whether to allow the energy storage charge and discharge operation in combination with the judgment result of the current overloaded / overlimit cross-section specifically includes: Receive the energy storage charge and discharge request, collect the current cross-section tidal current change amount and the current energy storage power change amount, and calculate the energy storage cross-section sensitivity as follows: In the formula, MGD represents the energy storage cross-section sensitivity; represents the current cross-section tidal current change amount; represents the current energy storage power change amount; If the energy storage cross-section sensitivity MGD of the current overloaded / overlimit cross-section in the charging state is ≥0, allow the energy storage charging operation; otherwise, prohibit the energy storage charging operation; If the energy storage cross-section sensitivity MGD of the current overloaded / overlimit cross-section in the discharging state is ≤0, allow the energy storage discharging operation; otherwise, prohibit the energy storage discharging operation.

[0009] Preferably, obtain the cross-section ID and the corresponding energy storage cross-section sensitivity, the current cross-section tidal current data, the current cross-section tidal current limit value, and the judgment result of the current overloaded / overlimit cross-section, and establish a cross-section data storage library.

[0010] Preferably, if the energy storage charge and discharge operation is allowed, calculate the maximum energy storage charge and discharge power based on the current cross-section tidal current data and the current cross-section tidal current limit value. Specifically includes: In the charging state, the calculation formula for the corresponding maximum energy storage charging power is as follows: In the formula, represents the maximum charging power of energy storage; represents the operation of taking the minimum value; represents the current section power flow limit; represents the current section power flow data; represents the current energy storage charging power; In the discharge state, the calculation formula for the corresponding maximum discharge power of the energy storage is as follows: In the formula, represents the maximum discharge power of the energy storage; represents the operation of taking the minimum value; represents the current section power flow limit; represents the current section power flow data; represents the current energy storage discharge power.

[0011] Preferably, the construction of the short-term load forecasting model and the determination of the predicted section power flow data based on the current section power flow data specifically include: Performing feature extraction on the current section power flow data to obtain the corresponding current section power flow features; Inputting the current section power flow features into the forgetting gate of the short-term load forecasting model to determine the current section power flow features that need to be discarded from the memory cell, and the corresponding calculation formula is as follows: In the formula, represents the output of the forgetting gate at the charging and discharging time t, which is used to determine the current section power flow features that need to be discarded from the memory cell; represents the activation function of the forgetting gate; represents the weight of the forgetting gate; represents the hidden state at the previous charging and discharging time t - 1; represents the current section power flow features input at the charging and discharging time t; represents the hidden state and the current section power flow features constitute a vector; represents the bias term of the forgetting gate; Based on the input gate of the short-term load forecasting model, determine the current section power flow features that need to be stored in the memory cell, and the corresponding calculation formula is as follows: In the formula, represents the output of the input gate at the charging and discharging time t, which is used to determine the current section power flow features that need to be stored in the memory cell; represents the activation function of the input gate; represents the weight of the input gate; Represents the hidden state at the previous charge-discharge time t-1; Represents the current section power flow characteristics input at the charge-discharge time t; Represents the hidden state And the current section power flow characteristics The vector formed; Represents the bias term of the input gate; Based on the candidate memory unit of the short-term load prediction model, determine the candidate section power flow characteristics, and the corresponding calculation formula is as follows: In the formula, Represents the candidate memory unit at the charge-discharge time t, used to determine the candidate section power flow characteristics; Represents the hyperbolic tangent function; Represents the weight of the candidate memory unit; Represents the hidden state at the previous charge-discharge time t-1; Represents the current section power flow characteristics input at the charge-discharge time t; Represents the hidden state And the current section power flow characteristics The vector formed; Represents the bias term of the candidate memory unit; The calculation formula for updating the memory unit is as follows: In the formula, Represents the memory unit at the charge-discharge time t; Represents the output of the forget gate at the charge-discharge time t; Represents the memory unit at the previous charge-discharge time t-1; Represents the output of the input gate at the charge-discharge time t; Represents the candidate memory unit at the charge-discharge time t; Based on the output gate of the short-term load prediction model, determine the candidate section power flow characteristics that need to be output to the hidden state, and the corresponding calculation formula is as follows: In the formula, Represents the output of the output gate at the charge-discharge time t, used to determine the candidate section power flow characteristics that need to be output to the hidden state; Represents the activation function of the output gate; Represents the weight of the output gate; Represents the hidden state at the previous charge-discharge time t-1; Represents the current section power flow characteristics input at the charge-discharge time t; Represents the hidden state And the current section power flow characteristics The vector formed; Represents the bias term of the output gate; Determine the predicted section power flow data according to the memory unit at the charge and discharge time t and the output of the output gate. The corresponding calculation formula is as follows: In the formula, represents the hidden state at the charge and discharge time t, that is, the predicted section power flow data ; represents the hyperbolic tangent function; represents the output of the output gate at the charge and discharge time t; represents the memory unit at the charge and discharge time t.

[0012] Preferably, discretize the total duration corresponding to the energy storage charge and discharge strategy at a preset time interval to obtain an energy storage time series; In the energy storage time series, obtain the predicted change in energy storage power at the charge and discharge time t , and combine it with the energy storage section sensitivity MGD to calculate the predicted change in section power flow at the charge and discharge time t ; The predicted section power flow data and the predicted change in section power flow The sum of them is the simulated section power flow data .

[0013] Preferably, based on the simulated section power flow data, if it is determined according to the preset heavy load / overlimit standard that there is a future heavy load / overlimit section, then sequentially reduce the predicted change in energy storage power , and shift the charge and discharge time t backward until there is no future heavy load / overlimit section, complete the adjustment process of the energy storage charge and discharge strategy, and send the adjusted energy storage charge and discharge strategy to the energy storage management terminal, or when the number of strategy adjustments reaches the maximum number of adjustments, send a charge and discharge strategy cancellation instruction to the energy storage management terminal.

[0014] Compared with the related technology, a method for optimizing the energy storage charge and discharge strategy based on sensitivity provided by the present invention has the following beneficial effects: The present invention can obtain the current section power flow data and the current section power flow limit value, and determine whether there is a current overloaded / overlimit section according to a preset heavy load / overlimit standard; receive the energy storage charge and discharge request, obtain the energy storage section sensitivity, and combine the judgment result of the current overloaded / overlimit section to determine whether to allow the energy storage charge and discharge operation; if the energy storage charge and discharge operation is allowed, calculate the maximum energy storage charge and discharge power based on the current section power flow data and the current section power flow limit value; construct a short-term load prediction model, and determine the predicted section power flow data according to the current section power flow data; construct an energy storage charge and discharge strategy based on the maximum energy storage charge and discharge power and calculate the predicted section power flow change amount, and combine the predicted section power flow data to obtain the simulated section power flow data; based on the simulated section power flow data, determine whether there is a future overloaded / overlimit section according to the preset heavy load / overlimit standard, and adjust the energy storage charge and discharge strategy, so as to realize the safety check, power optimization and dynamic adjustment of the energy storage charge and discharge, improve the real-time performance and dynamic adaptability of the energy storage charge and discharge plan, enhance the energy storage utilization efficiency, and ensure the safe operation of the power grid.

[0015] Under the current operation condition of the power grid, the present invention can quickly and accurately verify whether the energy storage can be charged and discharged, and thus can meet the safety check requirements for the energy storage charge and discharge and ensure the safety of the power grid. The present invention can accurately calculate the maximum energy storage charge and discharge power, avoid affecting the power grid stability due to unreasonable charge and discharge power, and thus improve the energy storage utilization efficiency. The present invention can adjust the energy storage charge and discharge plan to adapt to the dynamic changes of the future power grid, enhance the flexibility and adaptability of the energy storage charge and discharge strategy, and improve the safety and economy of the power grid operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a flowchart of a method for optimizing an energy storage charge and discharge strategy based on sensitivity according to the present invention; Figure 2 is a schematic diagram for sending an instruction to cancel the charge and discharge strategy according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The present invention will be further described below in conjunction with the drawings and embodiments.

[0018] As Figure 1 shown, a method for optimizing an energy storage charge and discharge strategy based on sensitivity, the method includes: Obtain the current section power flow data and the current section power flow limit value, and determine whether there is a current overloaded / overlimit section according to a preset heavy load / overlimit standard; In practical applications, the power flow data and the power flow limit value of the current section can be accurately obtained, and according to the preset heavy load / overlimit standard, it can be determined whether there is a current overloaded / overlimit section, so as to timely discover potential safety hazards in the operation process of the power grid.

[0019] Among them, the current cross-section power flow data refers to the real-time power flow data of the current power grid cross-section, specifically including parameters such as active power, reactive power, current, and voltage. These data reflect the actual power flow status of the current power grid at the cross-section and are the key basis for judging the operation status of the power grid and making relevant decisions.

[0020] For example, at a specific moment, the active power of a transmission line cross-section is 50 megawatts, the reactive power is 20 megavars, the current is 300 amperes, and the voltage is 110 kV. These data constitute the current cross-section power flow data of this cross-section, facilitating grid dispatching personnel to timely obtain the operation situation of the power grid.

[0021] Furthermore, the current cross-section power flow limit refers to the maximum power flow value allowed to pass through the cross-section determined in advance, which is set according to the design specifications of the power grid, the rated capacity of the equipment, and the requirements for the safe and stable operation of the power grid. It includes indicators such as active power limit and reactive power limit, and these indicators are important boundary conditions for ensuring the safe operation of the power grid.

[0022] When formulating these limits, multiple factors such as the thermal stability limit of the line, the insulation performance of the equipment, and the stability of the system need to be comprehensively considered. For example, the heat generation limit of the conductor of a certain transmission line determines the maximum current it allows to pass through, and thus the active power limit of this cross-section can be determined; while the reactive power limit is closely related to the voltage stability of the system. If the cross-section power flow exceeds the limit, problems such as line overheating, equipment damage, and power grid failures may occur.

[0023] It can be understood that the preset heavy load / overlimit standard refers to the rule used to judge whether the cross-section is in a heavy load or overlimit state. Among them, the heavy load standard is set that the cross-section power flow reaches more than 90% of the limit but does not exceed the limit, that is, when the cross-section power flow is greater than or equal to 90% of the limit but does not exceed the limit, then it is determined that this cross-section is in a heavy load state; and the overlimit standard is set that the cross-section power flow exceeds the limit. The preset heavy load / overlimit standard is an important basis in the operation management of the power grid and helps dispatching personnel quickly judge the safety of the power grid operation.

[0024] For example, the active power limit of a certain cross-section is 100 megawatts. According to the preset heavy load / overlimit standard, when the active power reaches 90 megawatts and above but less than 100 megawatts, this cross-section is in a heavy load state; if the active power exceeds 100 megawatts, it is in an overlimit state.

[0025] It should be noted that the current heavy load / overlimit cross-section refers to the cross-section in a heavy load or overlimit state determined according to the preset heavy load / overlimit standard. If the power flow data of a certain cross-section meets the heavy load standard, it is the current heavy load cross-section; if this cross-section meets the overlimit standard, it is the current overlimit cross-section.

[0026] Once the current overload / overlimit section is detected, grid dispatching personnel need to take corresponding measures in a timely manner, such as adjusting the generation plan, optimizing the load distribution, controlling the charge and discharge of energy storage, etc., to ensure that the power grid returns to a safe operating state and guarantee the power supply stability of the power system.

[0027] Receive the energy storage charge and discharge request, obtain the energy storage section sensitivity, and determine whether to allow the energy storage charge and discharge operation in combination with the judgment result of the current overload / overlimit section; When receiving the energy storage charge and discharge request, the energy storage section sensitivity can be obtained, and it is determined whether to allow the energy storage to perform the charge and discharge operation in combination with the judgment result of the current overload / overlimit section.

[0028] During the operation of the power system, the energy storage charge and discharge request refers to the charge and discharge command signal sent by the energy storage device to the grid control center so that it can achieve its own energy management and cooperate with the operation requirements of the power grid.

[0029] The energy storage section sensitivity is used to measure the influence degree of the energy storage charge and discharge behavior on the power grid section power flow. Different energy storage positions and charge and discharge powers have different influence degrees on the section power flow, and this influence degree is quantified by the energy storage section sensitivity.

[0030] For example, if the transmission lines near a certain energy storage connection point are relatively dense, then when this energy storage charges and discharges, the influence on the surrounding section power flow is relatively large, and the corresponding energy storage section sensitivity is relatively high; on the contrary, if the energy storage is located at the edge of the power grid and there are fewer surrounding lines, its charge and discharge have a relatively small influence on the power flow of other sections, and the energy storage section sensitivity is relatively low.

[0031] It should be noted that when performing the energy storage charging operation, the energy storage device absorbs electric energy from the power grid and stores it in the form of chemical energy, etc.; when performing the energy storage discharging operation, the energy storage device converts the stored energy into electric energy and injects it into the power grid to provide additional power support for the power system. Through the energy storage charge and discharge operation, the voltage can be regulated and the power grid power can be balanced, improving the power quality.

[0032] If the energy storage charge and discharge operation is allowed, calculate the maximum energy storage charge and discharge power based on the current section power flow data and the current section power flow limit value; If the judgment result allows the energy storage to perform the charge and discharge operation, at this time, the maximum energy storage charge and discharge power can be accurately calculated based on the current section power flow data and the current section power flow limit value to ensure that while meeting the energy storage requirements, it will not cause too much impact on the power grid.

[0033] It is understandable that the maximum charging and discharging power of energy storage refers to the maximum power that the energy storage device is allowed to reach during charging and discharging. It takes into account both the safety margin of the power grid and the charging and discharging requirements of the energy storage device itself, plays a key role in balancing the utilization of energy storage and the stable operation of the power grid, and provides an important power limit basis for the formulation of energy storage charging and discharging strategies.

[0034] Construct a short-term load forecasting model and determine the predicted section power flow data based on the current section power flow data; Among them, the predicted section power flow data refers to the power data of the future power grid section obtained through prediction. Based on the short-term load forecasting model, the predicted section power flow data can be determined according to the current section power flow data, which helps power dispatching personnel understand the future power flow distribution of the power grid in advance, judge whether there are potential safety hazards, and thus formulate countermeasures in advance.

[0035] Construct an energy storage charging and discharging strategy based on the maximum charging and discharging power of the energy storage, calculate the change in the predicted section power flow, and obtain the simulated section power flow data by combining the predicted section power flow data; For example, during the low load period, if the predicted section power flow data shows that there is surplus power and the maximum charging power of the energy storage allows, the energy storage charging and discharging strategy can arrange for the energy storage to charge and store the excess electrical energy; while during the high load period, when the predicted section power flow data indicates that the power supply is tight, the energy storage charging and discharging strategy will arrange for the energy storage to discharge at the maximum discharging power to supplement the power grid power. Thus, through reasonable charging and discharging arrangements, the power balance of the power grid can be optimized, and the stability and economy of the power grid operation can be improved.

[0036] The change in the predicted section power flow refers to the change in the predicted section power flow caused by the energy storage charging and discharging operation. When the energy storage charges or discharges, it will change the power distribution in the power grid, thereby causing a change in the section power flow.

[0037] When considering the energy storage charging and discharging, by superimposing the predicted power flow change amount on the original predicted section power flow data, the power flow distribution of the power grid section after the energy storage charging and discharging operation can be simulated.

[0038] Based on the simulated section power flow data, judge whether there is a future overloaded / overlimit section according to the preset overloaded / overlimit standard, and adjust the energy storage charging and discharging strategy.

[0039] In practical applications, based on the simulated section power flow data, it can be judged again whether there is a future overloaded / overlimit section according to the preset overloaded / overlimit standard. If this is the case, the energy storage charging and discharging strategy needs to be adjusted accordingly to ensure the safe and stable operation of the power grid in the future for a period of time.

[0040] The future overloaded / overlimit section refers to the section where overloaded or overlimit situations may occur in the future. If the simulated section power flow data meets the preset overload criteria, then the section is determined to be a future overloaded section; if the simulated section power flow data meets the preset overlimit criteria, then the section is determined to be a future overlimit section.

[0041] In the specific implementation process, the obtaining of the current section power flow data and the current section power flow limit value, and the judgment of whether there is a current overloaded / overlimit section according to the preset overload / overlimit criteria specifically includes: Based on the data acquisition and monitoring control system, the current section power flow data and the current section power flow limit value are collected in real time; Based on the preset overload / overlimit criteria, it is judged whether there is the current overloaded / overlimit section according to the current section power flow data and the current section power flow limit value, and the corresponding calculation formula is as follows: In the formula, PDJG represents the judgment result of the current overloaded / overlimit section; represents the current section power flow data; represents the current section power flow limit value.

[0042] In practical applications, based on the data acquisition and monitoring control system, through sensors and monitoring devices distributed at various key positions of the power grid, the current section power flow data and the current section power flow limit value can be collected in real time.

[0043] Immediately afterwards, based on the preset overload / overlimit criteria, combined with the collected current section power flow data and the current section power flow limit value, it is judged whether there is a current overloaded / overlimit section. If the current section power flow data is between 0.9 times the current section power flow limit value and the current section power flow limit value, the judgment result is that there is a current overloaded section; if the current section power flow data exceeds the current section power flow limit value, the judgment result is that there is a current overlimit section, so that it can be accurately judged whether there is an abnormality in the current power grid operation state.

[0044] The receiving of the energy storage charge and discharge request, the obtaining of the energy storage section sensitivity, and the determination of whether to allow the energy storage charge and discharge operation in combination with the judgment result of the current overloaded / overlimit section specifically includes: Receive the energy storage charge and discharge request, collect the current section power flow change amount and the current energy storage power change amount, and calculate the energy storage section sensitivity as follows: In the formula, MGD represents the energy storage section sensitivity; represents the current section power flow change amount; represents the current energy storage power change amount; If the energy storage section sensitivity MGD of the current heavy overload / overlimit section under the charging state is ≥0, energy storage charging operation is allowed; otherwise, the energy storage charging operation is prohibited. If the energy storage section sensitivity MGD of the current heavy overload / overlimit section under the discharging state is ≤0, energy storage discharging operation is allowed; otherwise, the energy storage discharging operation is prohibited.

[0045] After receiving the energy storage charge / discharge request, the current section power flow change and the current energy storage power change can be collected, and the energy storage section sensitivity can be calculated.

[0046] Then, based on the judgment result of the current heavy overload / overlimit section and the calculated energy storage section sensitivity, it can be determined whether to allow the energy storage charge / discharge operation. If the energy storage section sensitivity of the current heavy overload / overlimit section under the charging state is greater than or equal to 0, it means that energy storage charging will not aggravate the heavy overload or overlimit of the current section, and at this time, energy storage charging operation is allowed; conversely, if the sensitivity is less than 0, it indicates that charging may aggravate the section abnormality, and at this time, the energy storage charging is prohibited.

[0047] If the energy storage section sensitivity of the current heavy overload / overlimit section under the discharging state is less than or equal to 0, it indicates that energy storage discharging will not aggravate the heavy overload or overlimit of the section, and at this time, energy storage discharging operation is allowed; if the sensitivity is greater than 0, it means that discharging may aggravate the section abnormality, and at this time, discharging is prohibited.

[0048] Obtain the section ID and the corresponding energy storage section sensitivity, the current section power flow data, the current section power flow limit value, and the judgment result of the current heavy overload / overlimit section, and establish a section data storage library.

[0049] First, the unique identifier of each section, that is, the section ID, can be obtained. At the same time, collect the energy storage section sensitivity, the current section power flow data, the current section power flow limit value, and the judgment result of the current heavy overload / overlimit section corresponding to each section. Furthermore, these information can be integrated to establish a section data storage library, which is convenient for subsequent efficient management and application of the power grid section data.

[0050] For example, in the section data storage library, when the section ID is section 1, the corresponding energy storage section sensitivity, the current section power flow data, the current section power flow limit value, and the judgment result of the current heavy overload / overlimit section are respectively 、 、 、 , as shown in Table 1.

[0051] Table 1 Information situation table of section 1 in the section data storage library

[0052] If energy storage charge and discharge operations are allowed, calculate the maximum power of energy storage charge and discharge based on the current section power flow data and the current section power flow limit. Specifically, it includes: In the charging state, the calculation formula for the corresponding maximum energy storage charging power is as follows: In the formula, represents the maximum energy storage charging power; represents the minimum value operation; represents the current section power flow limit; represents the current section power flow data; represents the current energy storage charging power; In the discharging state, the calculation formula for the corresponding maximum energy storage discharging power is as follows: In the formula, represents the maximum energy storage discharging power; represents the minimum value operation; represents the current section power flow limit; represents the current section power flow data; represents the current energy storage discharging power.

[0053] Through the above method, it is possible to avoid the section power flow approaching or exceeding the limit due to excessive charge and discharge power, thereby maintaining the power balance of the power grid, improving the acceptance capacity of the power grid for energy storage charge and discharge, optimizing the application effect of energy storage in the power grid, and realizing the coordinated and stable operation of energy storage and the power grid.

[0054] Construct a short-term load forecasting model and determine the predicted section power flow data based on the current section power flow data. Specifically, it includes: Extract the features of the current section power flow data to obtain the corresponding current section power flow features; Input the current section power flow features into the forget gate of the short-term load forecasting model to determine the current section power flow features that need to be discarded from the memory unit. The corresponding calculation formula is as follows: In the formula, represents the output of the forget gate at the charge and discharge time t, which is used to determine the current section power flow features that need to be discarded from the memory unit; represents the activation function of the forget gate; represents the weight of the forget gate; represents the hidden state at the previous charge and discharge time t - 1; represents the current section power flow features input at the charge and discharge time t; represents the hidden state and the current section power flow features form a vector; Represents the bias term of the forget gate; Based on the input gate of the short-term load forecasting model, determine the current cross-section power flow characteristics to be stored in the memory unit, and the corresponding calculation formula is as follows: In the formula, Represents the output of the input gate at the charge and discharge time t, and is used to determine the current cross-section power flow characteristics to be stored in the memory unit; Represents the activation function of the input gate; Represents the weight of the input gate; Represents the hidden state at the previous charge and discharge time t-1; Represents the current cross-section power flow characteristics input at the charge and discharge time t; Represents the hidden state And the current cross-section power flow characteristics Composed vector; Represents the bias term of the input gate; Based on the candidate memory unit of the short-term load forecasting model, determine the candidate cross-section power flow characteristics, and the corresponding calculation formula is as follows: In the formula, Represents the candidate memory unit at the charge and discharge time t, and is used to determine the candidate cross-section power flow characteristics; Represents the hyperbolic tangent function; Represents the weight of the candidate memory unit; Represents the hidden state at the previous charge and discharge time t-1; Represents the current cross-section power flow characteristics input at the charge and discharge time t; Represents the hidden state And the current cross-section power flow characteristics Composed vector; Represents the bias term of the candidate memory unit; The calculation formula for updating the memory unit is as follows: In the formula, Represents the memory unit at the charge and discharge time t; Represents the output of the forget gate at the charge and discharge time t; Represents the memory unit at the previous charge and discharge time t-1; Represents the output of the input gate at the charge and discharge time t; Represents the candidate memory unit at the charge and discharge time t; Based on the output gate of the short-term load forecasting model, determine the candidate cross-section power flow characteristics to be output to the hidden state, and the corresponding calculation formula is as follows: In the formula, Represents the output of the output gate at the charge and discharge time t, which is used to determine the candidate section power flow characteristics to be output to the hidden state; Represents the activation function of the output gate; Represents the weight of the output gate; Represents the hidden state at the previous charge and discharge time t - 1; Represents the current section power flow characteristics input at the charge and discharge time t; Represents the hidden state and the current section power flow characteristics to form a vector; Represents the bias term of the output gate; According to the memory unit at the charge and discharge time t and the output of the output gate, determine the predicted section power flow data, and the corresponding calculation formula is as follows: In the formula, Represents the hidden state at the charge and discharge time t, that is, the predicted section power flow data ; Represents the hyperbolic tangent function; Represents the output of the output gate at the charge and discharge time t; Represents the memory unit at the charge and discharge time t.

[0055] First, the characteristics of the current section power flow data can be extracted, and mechanisms such as the forget gate and input gate can be used to effectively screen and retain key information, discard redundant data, and improve the memory and processing ability of the short-term load prediction model for effective information.

[0056] Furthermore, by updating the memory unit, the model can continuously learn and adapt to the changes in the power grid power flow, making the prediction results more in line with the actual situation.

[0057] In addition, by determining the candidate section power flow characteristics, the predicted section power flow data can be obtained, so as to accurately predict the change trend of the power grid power flow, provide a reliable basis for formulating the energy storage charge and discharge strategy, enhance the stability and reliability of the power grid operation, and improve the collaborative efficiency of the energy storage and the power grid.

[0058] Discretize the total duration corresponding to the energy storage charge and discharge strategy at a preset time interval to obtain an energy storage time series; In the energy storage time series, obtain the predicted energy storage power change amount at the charge and discharge time t , and combine it with the energy storage section sensitivity MGD to calculate the predicted section power flow change amount at the charge and discharge time t ; The predicted section power flow data and the predicted section power flow change amount The sum of them is the simulated section power flow data 。

[0059] Among them, the total duration of the energy storage charge-discharge strategy can be discretized, the charge-discharge process can be divided into multiple time points, and then the energy storage time series can be obtained. Then, the predicted cross-section power flow change can be calculated by combining the predicted change in energy storage power and the sensitivity of the energy storage cross-section, and the simulated cross-section power flow data can be obtained by combining the predicted cross-section power flow data, so that the operation status of the power grid after energy storage charge-discharge can be comprehensively simulated, and potential power grid operation risks can be revealed in advance.

[0060] Based on the simulated cross-section power flow data, if it is determined that there is a future overloaded / overlimit cross-section according to the preset overloaded / overlimit standard, the predicted change in energy storage power is sequentially reduced , and the charge-discharge time t is shifted backward until there is no future overloaded / overlimit cross-section, the adjustment process of the energy storage charge-discharge strategy is completed, and the adjusted energy storage charge-discharge strategy is sent to the energy storage management terminal, or the number of strategy adjustments reaches the maximum number of adjustments, and a charge-discharge strategy cancellation instruction is sent to the energy storage management terminal.

[0061] When it is determined that there is a future overloaded / overlimit cross-section, the energy storage charge-discharge strategy can be adjusted in a timely manner, effectively avoiding the risks of power grid overload or overlimit, ensuring the safe and stable operation of the power grid, achieving good coordination between the energy storage and the power grid, and improving the operation quality of the power grid.

[0062] It should be noted that a maximum number of adjustments is set here. When the total number of strategy adjustments reaches the maximum number of adjustments, as Figure 2 shown, the charge-discharge strategy cancellation instruction can be sent to the energy storage management terminal, that is, the staff responsible for energy storage management, in a timely manner through the terminal device, which can save computing resources, improve the energy storage utilization efficiency, and ensure the stability and orderliness of the power grid operation.

[0063] Through the introduction of the above embodiments, the present invention can obtain the current section power flow data and the current section power flow limit value based on the method of optimizing the energy storage charge and discharge strategy according to sensitivity, and determine whether there is a current overloaded / over-limit section according to the preset heavy load / over-limit standard; receive the energy storage charge and discharge request, obtain the energy storage section sensitivity, and combine the judgment result of the current overloaded / over-limit section to determine whether to allow the energy storage charge and discharge operation; if the energy storage charge and discharge operation is allowed, calculate the maximum energy storage charge and discharge power based on the current section power flow data and the current section power flow limit value; construct a short-term load prediction model, and determine the predicted section power flow data according to the current section power flow data; construct an energy storage charge and discharge strategy based on the maximum energy storage charge and discharge power and calculate the change in the predicted section power flow, and obtain the simulated section power flow data in combination with the predicted section power flow data; based on the simulated section power flow data, determine whether there is a future overloaded / over-limit section according to the preset heavy load / over-limit standard, and adjust the energy storage charge and discharge strategy, so as to realize the safety check, power optimization and dynamic adjustment of the energy storage charge and discharge, improve the real-time performance and dynamic adaptability of the energy storage charge and discharge plan, enhance the energy storage utilization efficiency, and ensure the safe operation of the power grid.

[0064] The present invention can quickly and accurately verify whether the energy storage can be charged and discharged under the current operating conditions of the power grid, and thus can meet the safety verification requirements of the energy storage charge and discharge and ensure the safety of the power grid. The present invention can accurately calculate the maximum energy storage charge and discharge power, avoid affecting the power grid stability due to unreasonable charge and discharge power, and thus improve the energy storage utilization efficiency. The present invention can adjust the energy storage charge and discharge plan to adapt to the dynamic changes of the future power grid, enhance the flexibility and adaptability of the energy storage charge and discharge strategy, and improve the safety and economy of the power grid operation.

[0065] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, and the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for realizing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0066] Those of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing relevant hardware through a program, and this program can be stored in a computer-readable storage medium. The storage medium includes read-only memory (ROM), random access memory (RAM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), one-time programmable read-only memory (OTPROM), electrically-erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc memories, magnetic disc memories, tape memories, or any other medium that can be used to carry or store data and is readable by a computer.

[0067] It should also be noted that the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, commodity or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, commodity or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the existence of another identical element in the process, method, commodity or device comprising the element.

Claims

1. A method for optimizing the energy storage charge and discharge strategy based on sensitivity, characterized in that The method includes: Obtain the current section power flow data and the current section power flow limit value, and determine whether there is a current overloaded / overlimit section according to the preset overloaded / overlimit standard; Receive the energy storage charge / discharge request, obtain the energy storage section sensitivity, and determine whether to allow the energy storage charge / discharge operation in combination with the judgment result of the current overloaded / overlimit section; If the energy storage charge / discharge operation is allowed, calculate the maximum energy storage charge / discharge power based on the current section power flow data and the current section power flow limit value; Construct a short-term load prediction model, and determine the predicted section power flow data according to the current section power flow data; Construct an energy storage charge / discharge strategy based on the maximum energy storage charge / discharge power and calculate the change in the predicted section power flow, and obtain the simulated section power flow data in combination with the predicted section power flow data; Based on the simulated section power flow data, determine whether there is a future overloaded / overlimit section according to the preset overloaded / overlimit standard, and adjust the energy storage charge / discharge strategy.

2. The method for optimizing the energy storage charge and discharge strategy based on sensitivity according to claim 1, wherein The obtaining of the current section power flow data and the current section power flow limit value, and determining whether there is a current overloaded / overlimit section according to the preset overloaded / overlimit standard specifically includes: Based on the data acquisition and monitoring control system, collect the current section power flow data and the current section power flow limit value in real time; Based on the preset overloaded / overlimit standard, determine whether there is the current overloaded / overlimit section according to the current section power flow data and the current section power flow limit value, and the corresponding calculation formula is as follows: In the formula, PDJG represents the judgment result of the current overload / overlimit section; represents the current section power flow data; represents the current section power flow limit value.

3. A method for optimizing the energy storage charge and discharge strategy based on sensitivity according to claim 1, characterized in that, The receiving of the energy storage charge / discharge request, obtaining the energy storage section sensitivity, and determining whether to allow the energy storage charge / discharge operation in combination with the judgment result of the current overloaded / overlimit section specifically includes: Receive the energy storage charge / discharge request, collect the change in the current section power flow and the change in the current energy storage power, and calculate the energy storage section sensitivity as follows: In the formula, MGD represents the sensitivity of the energy storage section; represents the change in the current section power flow; represents the change in the current energy storage power; If the energy storage section sensitivity MGD of the current overloaded / overlimit section in the charging state is ≥0, allow the energy storage charging operation, otherwise prohibit the energy storage charging operation; If the energy storage section sensitivity MGD of the current overloaded / overlimit section in the discharging state is ≤0, allow the energy storage discharging operation, otherwise prohibit the energy storage discharging operation.

4. A method for optimizing the energy storage charge and discharge strategy based on sensitivity as claimed in claim 1, wherein, Obtain the section ID and the corresponding energy storage section sensitivity, the current section power flow data, the current section power flow limit value, and the judgment result of the current overloaded / overlimit section, and establish a section data storage library.

5. A method for optimizing the energy storage charge and discharge strategy based on sensitivity according to claim 1, characterized in that, The if the energy storage charge / discharge operation is allowed, calculating the maximum energy storage charge / discharge power based on the current section power flow data and the current section power flow limit value specifically includes: In the charging state, the calculation formula for the corresponding maximum energy storage charging power is as follows: In the formula, represents the maximum charging power of energy storage; represents the operation of taking the minimum value; represents the current section power flow limit; represents the current section power flow data; represents the current energy storage charging power; In the discharging state, the calculation formula for the corresponding maximum energy storage discharging power is as follows: In the formula, represents the maximum power of energy storage discharge; represents the operation of taking the minimum value; represents the current section power flow limit; represents the current section power flow data; represents the current energy storage discharge power.

6. The method for optimizing the energy storage charge and discharge strategy based on sensitivity according to claim 1, wherein The constructing of the short-term load prediction model, and determining the predicted section power flow data according to the current section power flow data specifically includes: Extract the features of the current section power flow data to obtain the corresponding current section power flow features; Input the current section power flow characteristics into the forget gate of the short-term load forecasting model to determine the current section power flow characteristics to be discarded from the memory cell. The corresponding calculation formula is as follows: In the formula, represents the output of the forget gate at the charge and discharge time t, which is used to determine the current section power flow characteristics that need to be discarded from the memory unit; represents the activation function of the forget gate; represents the weight of the forget gate; represents the hidden state at the previous charge and discharge time t-1; represents the current section power flow characteristics input at the charge and discharge time t; represents the hidden state and the current section power flow characteristics to form a vector; represents the bias term of the forget gate; Based on the input gate of the short-term load forecasting model, determine the current section power flow characteristics to be stored in the memory cell. The corresponding calculation formula is as follows: In the formula, represents the output of the input gate at the charge-discharge moment t, and is used to determine the current cross-section power flow characteristics that need to be stored in the memory unit; represents the activation function of the input gate; represents the weight of the input gate; represents the hidden state at the previous charge-discharge moment t - 1; represents the current cross-section power flow characteristics input at the charge-discharge moment t; represents the hidden state and the current cross-section power flow characteristics to form a vector; represents the bias term of the input gate; Based on the candidate memory cell of the short-term load forecasting model, determine the candidate section power flow characteristics. The corresponding calculation formula is as follows: In the formula, represents the candidate memory unit at the charge-discharge moment t, which is used to determine the candidate section power flow characteristics; represents the hyperbolic tangent function; represents the weight of the candidate memory unit; represents the hidden state at the previous charge-discharge moment t-1; represents the current section power flow characteristics input at the charge-discharge moment t; represents the hidden state and the current section power flow characteristics to form a vector; represents the bias term of the candidate memory unit; The calculation formula for updating the memory cell is as follows: In the formula, represents the memory unit at the charge and discharge time t; represents the output of the forget gate at the charge and discharge time t; represents the memory unit at the previous charge and discharge time t - 1; represents the output of the input gate at the charge and discharge time t; represents the candidate memory unit at the charge and discharge time t; Based on the output gate of the short-term load forecasting model, determine the candidate section power flow characteristics to be output to the hidden state. The corresponding calculation formula is as follows: In the formula, represents the output of the output gate at the charge-discharge time t, which is used to determine the candidate section power flow characteristics to be output to the hidden state; represents the activation function of the output gate; represents the weight of the output gate; represents the hidden state at the previous charge-discharge time t - 1; represents the current section power flow characteristics input at the charge-discharge time t; represents the hidden state and the current section power flow characteristics to form a vector; represents the bias term of the output gate; According to the memory cell at the charge and discharge time t and the output of the output gate, determine the predicted section power flow data. The corresponding calculation formula is as follows: In the formula, represents the hidden state at the charge and discharge time t, that is, the predicted section power flow data ; represents the hyperbolic tangent function; represents the output of the output gate at the charge and discharge time t; represents the memory cell at the charge and discharge time t.

7. A method for optimizing the energy storage charge and discharge strategy based on sensitivity, characterized in that, Discretize the total duration corresponding to the energy storage charge and discharge strategy at a preset time interval to obtain an energy storage time series; In the energy storage time series, obtain the predicted change in energy storage power at the charging and discharging time t , and combine the energy storage section sensitivity MGD to calculate the predicted change in section power flow at the charging and discharging time t ; The predicted cross-section tidal current data and the change amount of the predicted cross-section tidal current The sum is the simulated cross-section tidal current data .

8. A method for optimizing the energy storage charge and discharge strategy based on sensitivity according to claim 7, characterized in that, Based on the simulated cross-section tidal current data, if it is determined according to the preset heavy load / overlimit standard that there is a future heavy load / overlimit cross-section, the predicted energy storage power change amount is sequentially reduced , the charge and discharge time t is shifted backward until there is no future heavy load / overlimit cross-section, the adjustment process of the energy storage charge and discharge strategy is completed, and the adjusted energy storage charge and discharge strategy is sent to the energy storage management terminal, or when the number of strategy adjustments reaches the maximum number of adjustments, a charge and discharge strategy cancellation instruction is sent to the energy storage management terminal.

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