Operation method and device for standby high-capacity energy storage for peak regulation and frequency modulation

Abstract

The invention discloses a high-capacity energy storage operation method and device for peak regulation and frequency modulation standby. The method comprises the steps that an energy storage target function is constructed with the minimum weighted least square peak regulation and frequency modulation deviation; acquiring peak regulation instruction power and frequency modulation instruction power; according to the peak regulation instruction power, calculating to obtain a peak regulation operation interval; calculating a frequency modulation operation interval according to the frequency modulation instruction power; obtaining a peak regulation and frequency modulation interval according to the peak regulation operation interval and the frequency modulation operation interval; performing rolling optimization calculation on the energy storage target function by taking the peak regulation and frequency modulation interval as a constraint condition to obtain an energy storage charge state; and determining an operation mode of high-capacity energy storage according to the energy storage charge state. According to the method, the relationship between the SOC for peak regulation and the SOC for frequency modulation of energy storage in each scheduling period can be coordinated, and the SOC required by high-capacity energy storage operation for peak regulation and frequency modulation standby in each current and subsequent scheduling periods is obtained by combining rolling optimization calculation, so that the problem of coordination control of existing energy storage, peak regulation and frequency modulation is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of power system control, and in particular to an operating method and device for large-capacity energy storage for peak load regulation and frequency regulation. Background Art

[0002] With the continuous development of new power systems, the power fluctuations caused by high penetration rates of wind and solar power generation have greatly affected the power balance of the power system. Among them, wind turbines and photovoltaics are connected to the grid through power electronic equipment, resulting in the decoupling of speed from system frequency and a decrease in system frequency level, which seriously threatens the safe, reliable and stable operation of the power grid. Energy storage has the advantages of precise control, rapid response, and flexible adjustment, and can play an important role in peak load regulation and frequency regulation of power systems. Therefore, in order to achieve a high proportion of wind power and photovoltaic power generation and ensure the safe operation of new power systems, it is necessary to increase energy storage to ensure the system's stability after conventional units are replaced.

[0003] At present, there have been many research results on the reasonable configuration of large-capacity energy storage and distributed energy storage. However, the research on large-capacity energy storage participating in the peak-shaving and frequency-regulating of power systems is basically that large-capacity energy storage alone realizes the peak-shaving operation of power systems or the peak-shaving operation of power systems, which has the following problems:

[0004] 1) There is a lack of control methods and strategies for achieving coordinated control of large-capacity energy storage when it participates in peak and frequency regulation of the power system.

[0005] 2) The method of independently allocating energy storage capacity for peak load regulation and frequency regulation is adopted. However, this method will cause the problem of idle energy storage capacity.

[0006] 3) Based on large-capacity energy storage participating in the secondary frequency regulation of the power system (responding to the power system AGC (Automatic Generation Control)) control. The main idea is to calculate the regulation amount of energy storage participating in the secondary frequency regulation of the power system through optimization methods under the known power system topology and short-term forecast of power supply and load, so as to arrange the operation of energy storage SOC in each time period. However, from the perspective of energy storage control, energy storage control is local control, and the topology and state of the power system are generally unobservable. Therefore, it is necessary to establish a control strategy for energy storage secondary frequency regulation based on the local information of the power grid where the energy storage is located. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide an operation method and device for large-capacity energy storage for peak-shaving and frequency-regulating standby, so as to solve the coordination control problem of existing energy storage for peak-shaving and frequency-regulating.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0009] An operating method for large-capacity energy storage for peak load regulation and frequency regulation, comprising:

[0010] The energy storage objective function is constructed with the goal of minimizing the weighted least square peak and frequency regulation deviation;

[0011] Obtain peak load command power and frequency regulation command power;

[0012] Calculating the peak load operation range according to the peak load instruction power;

[0013] Calculating the frequency modulation operation range according to the frequency modulation instruction power;

[0014] Obtaining a peak-shaving and frequency-modulation interval according to the peak-shaving operation interval and the frequency-modulation operation interval;

[0015] Perform rolling optimization calculation on the energy storage objective function with the peak-shaving and frequency-regulating interval as a constraint condition to obtain the energy storage charge state;

[0016] The operation mode of the large-capacity energy storage is determined according to the energy storage charge state.

[0017] In order to solve the above technical problems, another technical solution adopted by the present invention is:

[0018] A device for operating a large-capacity energy storage for peak-shaving and frequency-modulating standby includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, each step in the above-mentioned method for operating a large-capacity energy storage for peak-shaving and frequency-modulating standby is implemented.

[0019] The beneficial effects of the present invention are as follows: by taking the minimum weighted least squares peak-shaving and frequency regulation deviation as the optimization objective function, and calculating the peak-shaving and frequency regulation interval by the peak-shaving command power and the frequency regulation command power, the peak-shaving and frequency regulation interval is used as a constraint condition to calculate the energy storage objective function, so as to coordinate the relationship between the SOC used for peak shaving and the SOC used for frequency regulation in each scheduling period, and combining the rolling optimization calculation to obtain the SOC required for the operation of large-capacity energy storage used for peak shaving and frequency regulation standby in the current and subsequent scheduling periods, thereby solving the problem of coordinated control of existing energy storage peak shaving and frequency regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A flowchart of the steps of an operation method of a large-capacity energy storage for peak load regulation and frequency regulation standby in an embodiment of the present invention;

[0021] Figure 2 A system structure diagram of an operation method for implementing a large-capacity energy storage for peak load regulation and frequency regulation in an embodiment of the present invention;

[0022] Figure 3The present invention is a schematic diagram of the structure of an operating device for a large-capacity energy storage system for peak load regulation and frequency regulation in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in combination with the implementation modes and the accompanying drawings.

[0024] Please refer to Figure 1 , an operation method of a large-capacity energy storage for peak load regulation and frequency regulation, comprising:

[0025] The energy storage objective function is constructed by minimizing the deviation of peak and frequency regulation using weighted least squares method;

[0026] Obtain peak load command power and frequency regulation command power;

[0027] Calculating the peak load operation range according to the peak load instruction power;

[0028] Calculating the frequency modulation operation range according to the frequency modulation instruction power;

[0029] Obtaining a peak-shaving and frequency-modulation interval according to the peak-shaving operation interval and the frequency-modulation operation interval;

[0030] Perform rolling optimization calculation on the energy storage objective function with the peak-shaving and frequency-regulating interval as a constraint condition to obtain the energy storage charge state;

[0031] The operation mode of the large-capacity energy storage is determined according to the energy storage charge state.

[0032] From the above description, it can be seen that the beneficial effects of the present invention are: by taking the minimum weighted least squares peak-shaving and frequency regulation deviation as the optimization objective function, and calculating the peak-shaving and frequency regulation interval through the peak-shaving command power and the frequency regulation command power, the peak-shaving and frequency regulation interval is used as a constraint condition to calculate the energy storage objective function, so as to coordinate the relationship between the SOC used for peak shaving and the SOC used for frequency regulation in each scheduling period, and combine the rolling optimization calculation to obtain the SOC required for the operation of large-capacity energy storage used for peak shaving and frequency regulation standby in the current and subsequent scheduling periods, thereby solving the coordination control problem of existing energy storage peak shaving and frequency regulation.

[0033] Furthermore, the energy storage objective function is constructed with the goal of minimizing the weighted least squares peak and frequency regulation deviation, including:

[0034]

[0035] Among them, k1 and k2 are the relative weights of the least squares peak-shaving deviation and the least squares frequency-shaving deviation in the objective function; α and β are used to balance the order of magnitude of the least squares peak-shaving deviation and the least squares frequency-shaving deviation; N is the number of scheduling cycles in the rolling optimization calculation time window; γ is the number of AGC cycles in each scheduling cycle; Pbatt,j is the energy storage charge state of the i-th AGC cycle; P batt,j is the energy storage charge state of the i-th AGC cycle; P peak,i,ref is the energy storage peak load command power of the i-th scheduling cycle; P f,j,ref is the energy storage frequency modulation command power of the i-th AGC cycle;

[0036] The jth AGC cycle belongs to The energy storage peak load command power of a scheduling cycle, is the ceiling function.

[0037] From the above description, it can be seen that by setting weight values ​​for the least squares peak-shaving deviation and the least squares frequency regulation deviation, and setting parameter values ​​for balancing the order of magnitude of the least squares peak-shaving deviation and the least squares frequency regulation deviation, the relationship between the SOC for peak shaving and the SOC for frequency regulation can be effectively coordinated, thereby solving the problem of coordinated control of energy storage peak shaving and frequency regulation.

[0038] Furthermore, the peak load operation interval is calculated according to the peak load instruction power, including:

[0039]

[0040] in, is the lower limit of the energy storage peak-shaving SOC operation range corresponding to the jth AGC cycle; is the upper limit of the energy storage peak load SOC operation range corresponding to the jth AGC cycle; SOC min The lower limit of the energy storage SOC allowed to operate; SOC max is the upper limit of the energy storage SOC allowed to operate; T is the duration of the scheduling cycle; E N is the rated capacity of energy storage.

[0041] From the above description, it can be seen that the precise peak load operation range can be calculated through the scheduling cycle and relevant data such as the rated capacity of energy storage.

[0042] Furthermore, the frequency modulation operation range is obtained by calculating the frequency modulation instruction power:

[0043]

[0044] Among them, SOC j,min is the lower limit of the energy storage SOC operation range in the jth AGC cycle; SOC j,max is the upper limit of the energy storage SOC operation range in the jth AGC cycle; SOC min The lower limit of the energy storage SOC allowed to operate; SOC max is the upper limit of the energy storage SOC allowed to operate; T is the duration of the scheduling cycle; E Nis the rated capacity of energy storage.

[0045] From the above description, it can be seen that the accurate frequency regulation operation range can be calculated based on relevant data such as the dispatch cycle and the rated capacity of energy storage.

[0046] Further, obtaining the peak-shaving and frequency-modulation interval according to the peak-shaving operation interval and the frequency-modulation operation interval includes:

[0047] An intersection operation is performed on the peak shaving operation interval and the frequency modulation operation interval to obtain the peak shaving and frequency modulation interval.

[0048] It can be seen from the above description that by calculating the intersection of the peak-shaving operation interval and the frequency-modulation operation interval, an effective control interval that satisfies the frequency-modulation operation interval and the peak-shaving operation interval can be obtained.

[0049] Furthermore, the peak shaving operation interval and the frequency modulation operation interval are intersected to obtain the peak shaving and frequency modulation interval further including:

[0050] If the result of the intersection operation is an empty set, the upper and lower limits of the rated energy storage allowable operation are used as the peak-shaving and frequency-regulating interval.

[0051] From the above description, it can be seen that when the intersection of the calculated peak-shaving operation range and the frequency regulation operation range is an empty set, the rated upper and lower limits of the allowable operation of the energy storage are used as the peak-shaving and frequency regulation range to avoid the inability to obtain an effective peak-shaving and frequency regulation range, which makes the system unable to be effectively regulated.

[0052] Furthermore, performing rolling optimization calculation on the energy storage objective function with the peak-shaving and frequency-regulating interval as a constraint condition also includes:

[0053] Construct local power grid operation constraints based on local power grid data;

[0054] The energy storage objective function is subjected to rolling optimization calculation with the peak-shaving and frequency-regulating interval and the local power grid operation constraints as constraint conditions.

[0055] From the above description, it can be seen that by combining the local power grid operation constraints to perform rolling optimization calculations, the calculation results can meet the actual operation requirements of the power grid where the energy storage is located.

[0056] Furthermore, the local power grid operation constraints include:

[0057] Active power balance constraints:

[0058]

[0059] Where P Gij P is the active power of the i-th power supply in the j-th AGC cycle; batt,j P is the energy storage charge state of the jth AGC cycle;tie,j P is the power exchanged between the local power grid where the energy storage is located and the external large power grid in the jth AGC cycle; LD,j is the load value of energy storage in the jth AGC cycle;

[0060] Line active power flow constraints:

[0061] -P tie , N ≤P tie , j ≤P tie , N ;

[0062] Where P tie , N is the circuit thermal limit; P tie , j is the line active power in the jth AGC cycle;

[0063] Power active power constraints:

[0064] P Gij ≤P Gimax ;

[0065] Where P Gimax is the maximum active power of the i-th power supply.

[0066] From the above description, it can be seen that by combining the active power balance constraint, the line active power flow constraint and the power source active power constraint to calculate the energy storage charge state, the calculated energy storage charge state can meet the operating conditions of the local power grid.

[0067] Furthermore, the step of performing rolling optimization calculation on the energy storage objective function with the peak-shaving and frequency-regulating interval as a constraint condition to obtain the energy storage charge state also includes:

[0068] The energy storage objective function is subjected to rolling optimization calculation with a time window of 4h-6h.

[0069] From the above description, it can be seen that since the peak-shaving and frequency-regulating instructions are issued by the power grid dispatching, not generated locally, setting the time window to 4h-6h can make the dispatching cycle and calculation time window consistent with the power grid dispatching, ensuring that the optimization results are more reasonable.

[0070] Another embodiment of the present invention provides an operating device for large-capacity energy storage for peak shaving and frequency regulation and standby, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, each step in the operating method for large-capacity energy storage for peak shaving and frequency regulation and standby is implemented as described above.

[0071] The operation method and device of large-capacity energy storage for peak load and frequency regulation provided by the present invention can be applied to power grid energy storage optimization scenarios, mainly to secondary frequency regulation control scenarios, and are described below through specific implementation methods:

[0072] Embodiment 1

[0073] Please refer to Figure 1 , an operation method of a large-capacity energy storage for peak load regulation and frequency regulation, comprising:

[0074] S1. Construct the energy storage objective function with the goal of minimizing the weighted least squares peak-shaving and frequency-regulating deviation; Since the energy storage is subject to the energy storage charging and discharging constraints when responding to the peak-shaving command and the frequency-regulating command at the same time, at any time, the energy storage cannot be both charged and discharged, and it must either be only charged or only discharged; that is, the energy storage is mutually constrained when responding to the peak-shaving command and the frequency-regulating command at the same time; Note that the peak-shaving time scale is long (generally 30 minutes, 15 minutes), and the frequency-regulating time scale is short (generally about 1 to 5 minutes), so the energy storage response to the peak-shaving command determines the charging and discharging state of the energy storage; The energy storage response to the frequency-regulating command is to adjust the energy storage active power value up and down on the basis of satisfying the peak-shaving balance. When the energy storage responds to the peak-shaving command and the frequency-regulating command at the same time, if the peak-shaving command and the frequency-regulating command have large adjustment amounts (for example, the total adjustment amount of the peak-shaving command and the frequency-regulating command is greater than the amount of energy stored in the energy storage, the total power is greater than the energy storage climbing power, etc.), the energy storage cannot fully respond to the peak-shaving command and the frequency-regulating command; At this time, the degree of coordination of the response to the peak-shaving command and the frequency-regulating command is required, and the response reliability is reduced. This embodiment considers that the energy storage should respond to the peak load and frequency regulation instructions as much as possible. At the same time, because the energy storage charging and discharging is limited by the power of the power supply (or / and the tie line), the least square peak load and frequency regulation deviation is minimized as the objective function to determine a reasonable energy storage SOC value as the operation target for each scheduling cycle and arrange the operation mode. The energy storage objective function is specifically as follows:

[0075]

[0076] Among them, k1 and k2 are the relative weights of the least squares peak-shaving deviation and the least squares frequency regulation deviation in the objective function, which are used to emphasize the preference for the reliability of peak-shaving and frequency regulation responses when the peak-shaving and frequency regulation requirements of the power grid cannot be met at the same time, satisfying k1+k2=1; α and β are used to balance the order of magnitude of the least squares peak-shaving deviation and the least squares frequency regulation deviation; N is the number of dispatch cycles in the rolling optimization calculation time window. According to the current dispatch cycle, it is generally 15 minutes or 30 minutes, and the rolling optimization calculation time window is generally 4 hours or 6 hours. Therefore, N can be 8, 12, 16 or 24; γ is the AGC cycle in each dispatch cycle. For example, if the AGC cycle is 3 minutes and the dispatch cycle is 15 minutes, then γ can be taken as 5. Since the peak-shaving and frequency-regulating instructions are issued by the grid dispatch, not generated locally, it is most reasonable for the dispatch cycle and calculation time window to be consistent with the grid dispatch. Although the energy storage monitoring system can also use a shorter cycle and time window (must be exactly "dispatching time / N", N is an integer), too short a dispatch cycle and calculation time window require the decomposition of the dispatch instructions. More importantly, the optimization of the energy storage SOC is a full-time optimization problem. In theory, a longer time will produce better results, that is, too short a time will affect the optimization results.

[0077] P batt,j is the energy storage charge state of the i-th AGC cycle; P batt,j is the energy storage charge state of the i-th AGC cycle; P peak,i,ref P is the energy storage peak load command power in the ith scheduling period, which is generally given in the day-ahead plan; f,j,ref is the energy storage frequency regulation command power of the i-th AGC cycle, which needs to be predicted based on the frequency regulation data of similar historical scenarios;

[0078] The jth AGC cycle belongs to The energy storage peak load command power of a scheduling cycle, is the ceiling function.

[0079] S2. Obtain the peak load instruction power and frequency regulation instruction power. The peak load instruction issued by the power system to the energy storage is generally issued on the day before, and there is a peak load instruction value in each dispatching cycle during the peak load period of the next day. However, the frequency regulation instruction is issued in real time according to the operating frequency of the power grid. That is, the energy storage can know the peak load instruction value P during operation. peak,j,ref , but it is impossible to determine the future frequency modulation command value P in this scheduling cycle f,j,ref , frequency modulation command value P f,j,ref It is necessary to make predictions based on historical frequency modulation data; predict the frequency modulation command value P for several future AGC cycles f,j,refIt can be predicted based on the frequency modulation data of similar historical scenarios. Its principles and methods are similar to those of load forecasting and new energy output forecasting. Conventional load forecasting and new energy output forecasting methods can be used; for example, classic trend extrapolation methods, linear regression methods, time series methods, neural network methods, optimal combination forecasting methods, etc., or artificial intelligence methods such as prediction methods based on deep learning, artificial intelligence prediction methods based on mathematical and physical models, etc.

[0080] S3. Calculate the peak load operation range according to the peak load instruction power. The specific calculation method is as follows:

[0081]

[0082] in, is the lower limit of the energy storage peak-shaving SOC operation range corresponding to the jth AGC cycle; is the upper limit of the energy storage peak load SOC operation range corresponding to the jth AGC cycle; SOC min The lower limit of the energy storage SOC allowed to operate, generally set to 0.1; SOC max is the upper limit of the energy storage SOC allowed to operate, which is generally 0.9; T is the duration of the scheduling cycle, which is generally 0.25h or 0.5h; E N is the rated capacity of energy storage.

[0083] S4. Calculate the frequency modulation operation range according to the frequency modulation instruction power. The specific calculation method is as follows:

[0084]

[0085] Among them, SOC j,min is the lower limit of the energy storage SOC operation range in the jth AGC cycle; SOC j,max It is the upper limit of the energy storage SOC operation range in the jth AGC cycle.

[0086] S5. Obtain a peak-shaving and frequency-modulation interval according to the peak-shaving operation interval and the frequency-modulation operation interval. In this embodiment, the peak-shaving operation interval and the frequency-modulation operation interval are intersected to obtain the peak-shaving and frequency-modulation interval, as follows:

[0087]

[0088] like Then [SOC j,min ,SOC j,max ]=[SOC min ,SOC max ];

[0089] Among them, [SOC j,min ,SOC j,max] indicates the peak and frequency modulation interval, SOC j,min is the lower limit of the energy storage SOC operation range in the jth AGC cycle; SOC j,max It is the upper limit of the energy storage SOC operation range in the jth AGC cycle.

[0090] S6. Perform rolling optimization calculation on the energy storage objective function with the peak-shaving and frequency-regulating interval as the constraint condition to obtain the energy storage charge state, such as using 4-6 hours as the calculation time window, once per scheduling cycle as the calculation frequency, and using the initial SOC of the current scheduling cycle monitored as the initial value;

[0091] Please refer to Figure 2 The local system where the large-capacity energy storage is located is composed of various power stations (wind farms, solar photovoltaic power plants, etc.), energy storage, loads, interconnection lines and busbars connected to the large system. Among them, various power stations and interconnection lines can charge energy storage, and energy storage can discharge loads or / and the large system. The large-capacity energy storage monitoring system collects the active power of various power stations, energy storage, loads, and interconnection lines connected to the large system in real time, such as the active power P of the photovoltaic power station. PV , the active power P of the wind farm w , the active power P of energy storage batt , the load value of energy storage P LD , Interconnection line switching power P tie , energy storage SOC and other operating parameters, switch status and other data.

[0092] When performing rolling optimization calculations, the local grid operation constraints where the energy storage is located and the energy storage operation constraints are included; the local grid operation constraints include:

[0093] Active power balance constraints:

[0094]

[0095] Where P Gij P is the active power of the i-th power supply in the j-th AGC cycle; batt,j is the energy storage charge state of the energy storage in the jth AGC cycle, and the energy storage discharge is positive; P tie,j The power exchanged between the local power grid where the energy storage is located and the external large power grid tie line in the jth AGC cycle, and the injection is positive; P LD,j is the load value of energy storage in the jth AGC cycle; where the power source includes photovoltaic power stations and wind farms, that is, P PV,j is the active power of the PV power station in the jth AGC cycle; P w,j is the active power of the wind farm in the jth AGC cycle.

[0096] Line active power flow constraints:

[0097] -Ptie , N ≤P tie , j ≤P tie , N ;

[0098] Where P tie , N is the circuit thermal limit; P tie , j is the line active power in the jth AGC cycle;

[0099] Power active power constraints:

[0100] P Gij ≤P Gimax ;

[0101] Right now:

[0102] P PV,j ≤P PV,j,max ;

[0103] P w,j ≤P w,j,max ;

[0104] Where P Gimax is the maximum active power of the i-th power source. For new energy power sources, the maximum active power is its predicted power; P PV,j,max The active power of the photovoltaic power station is predicted for the jth AGC cycle; P w,j,max Predict the active power of the wind farm for the jth AGC cycle;

[0105] Energy storage operation constraints include:

[0106] SOC j ∈[SOC min ,SOC max ];

[0107] In the formula, SOC j is the SOC value of energy storage in the jth AGC cycle.

[0108] S7, determine the operation mode of large-capacity energy storage according to the energy storage charge state; that is, use the SOC calculated in step S6 to reasonably arrange the charge and discharge operation mode of the energy storage in the current scheduling cycle and the next scheduling cycle. Among them, the specific regulation principle of energy storage charge and discharge operation is as follows:

[0109] For the power system, energy storage discharge can be regarded as the power source of the power system; energy storage charging can be regarded as the load of the power system; when energy storage is used for peak load regulation, energy storage discharge is required during the peak load period of the power system; energy storage charging is required during the valley load period of the power system; when energy storage is used for frequency regulation, energy storage charging is required to reduce the frequency of the power system; and energy storage discharge is required to increase the frequency of the power system. However, whether it is peak load regulation or frequency regulation, the charging and discharging of energy storage requires a certain charging and discharging capacity of the energy storage, that is, it requires an appropriate SOC for charging and discharging. When the energy storage is charged, the amount of electricity stored in the energy storage is calculated according to ∫P batt,j As dt increases, SOC increases; when the energy storage is discharged, the amount of energy stored in the energy storage increases according to ∫P batt,j As dt decreases, SOC decreases. It can be seen that:

[0110] 1) Whether energy storage is used for peak load regulation or frequency regulation, it will cause SOC changes;

[0111] 2) The size of energy storage SOC affects the duration of peak load regulation and frequency regulation;

[0112] 3) Charging and discharging the energy storage affects the energy storage SOC and changes the active power balance of the local power grid where the energy storage is located, thereby changing the active power balance of the entire power system, thereby achieving peak load and frequency regulation.

[0113] Embodiment 2

[0114] Please refer to Figure 3 , an operating device for large-capacity energy storage for peak-shaving and frequency-regulating standby, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, each step of the operating method for large-capacity energy storage for peak-shaving and frequency-regulating standby as described in Example 1 is implemented.

[0115] In summary, the operation method and device of the large-capacity energy storage for peak-shaving and frequency-regulating standby provided by the present invention, based on the local power grid information where the energy storage is located, the large-capacity energy storage monitoring system takes the minimum weighted least squares peak-shaving and frequency-regulating deviation as the optimization objective function, and performs rolling optimization calculation on the SOC required for the large-capacity energy storage for peak-shaving and frequency-regulating standby operation in the current and subsequent scheduling periods, and can coordinate the relationship between the SOC for peak-shaving and the SOC for frequency regulation of the energy storage in each scheduling period, thereby achieving the following beneficial effects:

[0116] 1. Effectively solve the current lack of control methods and control strategies for peak and frequency coordinated control of energy storage using local information of the power grid where the energy storage is located.

[0117] 2. The optimization method with the least square peak-shaving and frequency regulation deviation as the objective function is used to determine the energy storage operation SOC. It can reasonably arrange the peak-shaving and frequency regulation according to the user's preference for peak-shaving and frequency regulation, thereby improving the response reliability of the peak-shaving and frequency regulation instructions, which has a significant effect on the safe operation of the power system.

[0118] 3. It avoids the waste of capacity caused by pre-allocating peak-shaving capacity and frequency regulation capacity for peak-shaving and frequency regulation, improves the utilization rate of energy storage, and brings additional ancillary service benefits to users.

[0119] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for operating large-capacity energy storage for peak load regulation and frequency regulation, characterized in that: include: The energy storage objective function is constructed with the goal of minimizing the weighted least square peak and frequency regulation deviation; Obtain peak load command power and frequency regulation command power; Calculating the peak load operation range according to the peak load instruction power; Calculating the frequency modulation operation range according to the frequency modulation instruction power; Obtaining a peak-shaving and frequency-modulation interval according to the peak-shaving operation interval and the frequency-modulation operation interval; Perform rolling optimization calculation on the energy storage objective function with the peak-shaving and frequency-regulating interval as a constraint condition to obtain the energy storage charge state; The operation mode of the large-capacity energy storage is determined according to the energy storage charge state.

2. The method for operating a large-capacity energy storage for peak load regulation and frequency regulation according to claim 1, characterized in that: The energy storage objective function is constructed with the goal of minimizing the weighted least square peak and frequency regulation deviation, including: Among them, k1 and k2 are the relative weights of the least squares peak-shaving deviation and the least squares frequency-shaving deviation in the objective function; α and β are used to balance the order of magnitude of the least squares peak-shaving deviation and the least squares frequency-shaving deviation; N is the number of scheduling cycles in the rolling optimization calculation time window; γ is the number of AGC cycles in each scheduling cycle; P batt,j is the energy storage charge state of the i-th AGC cycle; P batt,j is the energy storage charge state of the i-th AGC cycle; P peak,i,ref is the energy storage peak load command power of the i-th scheduling cycle; P f,j,ref is the energy storage frequency modulation command power of the i-th AGC cycle; The jth AGC cycle belongs to The energy storage peak load command power of a scheduling cycle, is the ceiling function.

3. The method for operating a large-capacity energy storage for peak load regulation and frequency regulation according to claim 2, characterized in that: The peak load operation interval is calculated according to the peak load instruction power, comprising: in, is the lower limit of the energy storage peak-shaving SOC operation range corresponding to the jth AGC cycle; is the upper limit of the energy storage peak load SOC operation range corresponding to the jth AGC cycle; SOC min The lower limit of the energy storage SOC allowed to operate; SOC max is the upper limit of the energy storage SOC allowed to operate; T is the duration of the scheduling cycle; E N is the rated capacity of energy storage.

4. The method for operating a large-capacity energy storage for peak load regulation and frequency regulation according to claim 2, characterized in that: The frequency modulation operation range is obtained by calculating the frequency modulation instruction power, comprising: Among them, SOC j,min is the lower limit of the energy storage SOC operation range in the jth AGC cycle; SOC j,max is the upper limit of the energy storage SOC operation range in the jth AGC cycle; SOC min The lower limit of the energy storage SOC allowed to operate; SOC max is the upper limit of the energy storage SOC allowed to operate; T is the duration of the scheduling cycle; E N is the rated capacity of energy storage.

5. The method for operating a large-capacity energy storage for peak load regulation and frequency regulation according to claim 1, characterized in that: The obtaining of the peak shaving and frequency modulation interval according to the peak shaving operation interval and the frequency modulation operation interval comprises: An intersection operation is performed on the peak shaving operation interval and the frequency modulation operation interval to obtain the peak shaving and frequency modulation interval.

6. The method for operating a large-capacity energy storage for peak load regulation and frequency regulation according to claim 5, characterized in that: The peak shaving operation interval and the frequency modulation operation interval are intersected to obtain the peak shaving and frequency modulation interval further comprising: If the result of the intersection operation is an empty set, the upper and lower limits of the rated energy storage allowable operation are used as the peak-shaving and frequency regulation interval.

7. The method for operating a large-capacity energy storage for peak load regulation and frequency regulation according to claim 1, characterized in that: The rolling optimization calculation of the energy storage objective function with the peak-shaving and frequency-regulating interval as a constraint condition further includes: Construct local power grid operation constraints based on local power grid data; The energy storage objective function is subjected to rolling optimization calculation with the peak-shaving and frequency-regulating interval and the local power grid operation constraints as constraint conditions.

8. The method for operating a large-capacity energy storage for peak load regulation and frequency regulation according to claim 7, characterized in that: The local power grid operation constraints include: Active power balance constraints: Where P Gij P is the active power of the i-th power supply in the j-th AGC cycle; batt,j P is the energy storage charge state of the jth AGC cycle; tie,j P is the power exchanged between the local power grid where the energy storage is located and the external large power grid in the jth AGC cycle; LD,j is the load value of energy storage in the jth AGC cycle; Line active power flow constraints: -P tie , N ≤P tie , j ≤P tie , N ; Where P tie , N is the circuit thermal limit; P tie , j is the line active power in the jth AGC cycle; Power active power constraints: P Gij ≤P Gimax ; Where P Gimax is the maximum active power of the i-th power supply.

9. The method for operating a large-capacity energy storage for peak load regulation and frequency regulation according to claim 1, characterized in that: The step of performing rolling optimization calculation on the energy storage objective function with the peak-shaving and frequency-regulating interval as a constraint condition to obtain the energy storage charge state further includes: The energy storage objective function is subjected to rolling optimization calculation with a time window of 4h-6h.

10. An operating device for large-capacity energy storage for peak load regulation and frequency regulation, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, each step of the method for operating a large-capacity energy storage for peak-shaving, frequency-regulating and standby is implemented as described in any one of claims 1 to 9.

Images