Distributed energy storage control method and system considering distribution transformer losses

Abstract

The present invention discloses a distributed energy storage control method and system that takes distribution transformer losses into account, including obtaining historical data information of a target power system; calculating the comprehensive power economic load factor of the distribution transformer and the corresponding optimal economic operation range; statistically analyzing the time data when the distribution transformer load rate is above and below the optimal economic operation range based on the distribution transformer load data of several historical days; statistically analyzing the power data when the distribution transformer load rate is above and below the optimal economic operation range; setting the discharge threshold, charging threshold, and output power of the distributed energy storage; and completing the control of the distributed energy storage of the target power system based on the set discharge threshold, charging threshold, and output power of the distributed energy storage. The present invention not only realizes distributed energy storage control that takes distribution transformer losses into account, but also has higher reliability, better accuracy, and higher overall efficiency of the power system.

Description

Technical Field

[0001] The present invention belongs to the field of electrical automation, and in particular relates to a distributed energy storage control method and system taking distribution transformer losses into consideration. Background Art

[0002] With the development of economy and technology and the improvement of people's living standards, electricity has become an indispensable secondary energy source in people's production and life, bringing endless convenience to people's production and life. Therefore, ensuring a stable and reliable supply of electricity has become one of the most important tasks of the power system.

[0003] Currently, more and more renewable energy power generation systems are being integrated into the power system and generating electricity. As the penetration rate of renewable energy continues to rise, the operating pressure on the power system is gradually increasing. Therefore, connecting distributed energy storage systems to the substations below the distribution transformers has become a highly efficient solution for the power system.

[0004] Distribution networks have a large number of distribution transformers; therefore, distribution transformer losses account for 40% of transmission and distribution losses. Currently, control schemes for distributed energy storage systems often only consider peak load shaving and valley filling for distribution transformers, as well as control objectives such as integrating new energy sources and promoting their consumption. However, under the control schemes of these distributed energy storage systems, distribution transformers often operate in a range with high overall losses. This significantly increases the overall losses of distribution transformers, thereby reducing the operating efficiency of the power system. Summary of the Invention

[0005] One of the objectives of the present invention is to provide a distributed energy storage control method that takes distribution transformer losses into consideration and has high reliability, good accuracy and high efficiency.

[0006] A second object of the present invention is to provide a system for implementing the distributed energy storage control method taking distribution transformer losses into consideration.

[0007] The distributed energy storage control method considering distribution transformer losses provided by the present invention comprises the following steps:

[0008] S1. Obtain historical data information of the target power system;

[0009] S2. According to the data information obtained in step S1, based on the active no-load loss, active short-circuit loss and load fluctuation loss of the distribution transformer, the comprehensive power economic load factor of the distribution transformer and the corresponding optimal economic operation range are calculated;

[0010] S3. Based on several days of historical distribution transformer load data, obtain statistical data on the time periods when the distribution transformer load factor was above and below the optimal economic operating range;

[0011] S4 according to the time data obtained in step S3, the distribution transformer load rate is statistically obtained when the power data is higher and lower than the optimal economic operating range;

[0012] S5. According to the relationship between the power data when the distribution transformer load rate is higher than the optimal economic operating range and the power data when the distribution transformer load rate is lower than the optimal economic operating range obtained in step S4, the discharge threshold, charging threshold and output power of the distributed energy storage are set based on the comprehensive power economic load factor of the distribution transformer, power data and time data;

[0013] S6. Complete the control of the distributed energy storage of the target power system according to the discharge threshold, charge threshold, and output power of the distributed energy storage set in step S5.

[0014] The step S2 specifically includes the following steps:

[0015] The comprehensive power economic load factor of the distribution transformer is calculated using the following formula: : In the formula is the active no-load loss of the distribution transformer; is the load fluctuation loss coefficient of the distribution transformer; is the active short-circuit loss of the distribution transformer;

[0016] Since the distribution transformer is operated at 75% load as the upper limit of the optimal economic operation zone, and the other point with the same comprehensive power loss rate as the upper limit of the optimal economic operation zone is the lower limit of the optimal operation zone, the upper limit load factor of the optimal economic operation range of the distribution transformer is obtained. The lower limit load factor of the optimal economic operation range of the distribution transformer is 0.75. for .

[0017] The step S3 specifically includes the following steps:

[0018] Obtain the load rate data of the distribution transformer within the historical T days, set the daily load sampling points to N, and the load rate curve of the historical day j is Expressed as , is the load rate of the distribution transformer at the i-th sampling point on the j-th day in history, , ;

[0019] According to the load rate curve of the distribution transformer, the load rate of the distribution transformer in the historical T days is greater than the upper limit load factor of the optimal economic operation range. The number of sampling points , and the load factor of the distribution transformer in the history of T days is less than the lower limit load factor of the optimal economic operation range The number of sampling points .

[0020] The step S4 specifically includes the following steps:

[0021] According to the time data obtained in step S3, the power data when the load rate of the distribution transformer is higher than the optimal economic operation range is calculated. : According to the time data obtained in step S3, the power data when the load rate of the distribution transformer is lower than the optimal economic operation range is calculated. : In the formula is the rated capacity of the distribution transformer.

[0022] The step S5 comprises the following steps:

[0023] If the power data and power data If the values ​​are equal, the charge and discharge thresholds of the distributed energy storage system on the substation side are set to the upper and lower load factors of the optimal economic operation zone of the distribution transformer, and the distribution transformer is set to operate in the optimal economic operation zone;

[0024] If the power data Greater than power data , then the charge and discharge thresholds of the distributed energy storage system on the substation side are set to the upper and lower limit load factors of the optimal economic operation zone of the distribution transformer, and the charging capacity of the distributed energy storage system on the substation side is increased when the distribution network is off;

[0025] If the power data Less than power data , the charge and discharge thresholds of the distributed energy storage system on the substation side are set to the upper and lower limit load factors of the optimal economic operation zone of the distribution transformer, and the discharge capacity of the distributed energy storage system on the substation side is increased during the peak period of the distribution network.

[0026] When power data and power data Equal, use the following steps to set up distributed energy storage:

[0027] Set the discharge threshold of the distributed energy storage system to ;

[0028] Set the charging threshold of the distributed energy storage system to ;

[0029] Set the output power of the distributed energy storage system for: Where is the real-time load rate of the distribution transformer at time t in the future;

[0030] At this time, the load rate curve of the optimized distribution transformer is for ;

[0031] When power data Greater than power data When using distributed energy storage, use the following steps to set up distributed energy storage:

[0032] Set the discharge threshold of the distributed energy storage system to ;

[0033] Set the charging threshold of the distributed energy storage system to ;

[0034] Set the output power of the distributed energy storage system for ;

[0035] At this time, the load rate curve of the optimized distribution transformer is for ;

[0036] When power data Less than power data When using distributed energy storage, use the following steps to set up distributed energy storage:

[0037] Set the discharge threshold of the distributed energy storage system to ;

[0038] Set the charging threshold of the distributed energy storage system to ;

[0039] Set the output power of the distributed energy storage system for ;

[0040] At this time, the load rate curve of the optimized distribution transformer is for .

[0041] The present invention also provides a system for implementing the distributed energy storage control method considering distribution transformer loss, comprising a data acquisition module, a first calculation module, a time statistics module, a power statistics module, a parameter setting module and an energy storage control module; the data acquisition module, the first calculation module, the time statistics module, the power statistics module, the parameter setting module and the energy storage control module are connected in series in sequence; the data acquisition module is used to acquire historical data information of the target power system and upload the data information to the first calculation module; the first calculation module is used to calculate the comprehensive power economic load factor of the distribution transformer and the corresponding optimal economic operation range based on the active no-load loss, active short-circuit loss and load fluctuation loss of the distribution transformer according to the received data information, and upload the data information to the time statistics module; the time statistics module is used to obtain the distribution transformer load rate based on the received data information and the distribution transformer load data of several days in history. The power statistics module is used to obtain the power data when the load rate of the distribution transformer is higher than and lower than the optimal economic operation range according to the received data information and the obtained time data, and upload the data information to the power statistics module; the power statistics module is used to obtain the power data when the load rate of the distribution transformer is higher than and lower than the optimal economic operation range according to the received data information and the obtained time data, and upload the data information to the parameter setting module; the parameter setting module is used to set the discharge threshold, charging threshold and output power of the distributed energy storage based on the received data information and the relationship between the power data when the load rate of the distribution transformer is higher than the optimal economic operation range and the power data when the load rate of the distribution transformer is lower than the optimal economic operation range, based on the comprehensive power economic load factor, power data and time data of the distribution transformer, and upload the data information to the energy storage control module; the energy storage control module is used to complete the control of the distributed energy storage of the target power system according to the received data information and the set discharge threshold, charging threshold and output power of the distributed energy storage.

[0042] The distributed energy storage control method and system that takes distribution transformer losses into account, provided by the present invention, obtains the optimal economic operating range and comprehensive power economic load factor of the distribution transformer by analyzing the historical data of the distribution transformer, and sets the control parameters of the distributed energy storage in real time based on the historical power data and working status of the distribution transformer. Therefore, the present invention not only realizes distributed energy storage control that takes distribution transformer losses into account, but also has higher reliability, better accuracy, and higher overall efficiency of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Schematic diagram of the process flow of the present invention.

[0044] Figure 2 Schematic diagram of the comprehensive loss curve of the distribution transformer in the method of the present invention.

[0045] Figure 3Schematic diagram of apparent power curve of distribution transformer according to the method embodiment of the present invention.

[0046] Figure 4 This is a schematic diagram of the apparent power curve of the distribution transformer without an energy storage device according to an embodiment of the method of the present invention.

[0047] Figure 5 This is a schematic diagram of the actual power curve of the distribution transformer in an embodiment of the method of the present invention in which an energy storage device is added and the energy storage control strategy does not consider the distribution transformer loss.

[0048] Figure 6 This is a schematic diagram of the energy storage output power curve when an energy storage device is added and the energy storage control strategy does not consider the distribution transformer loss in the embodiment of the method of the present invention.

[0049] Figure 7 This is a schematic diagram of the actual power curve of the distribution transformer in an embodiment of the method of the present invention in which an energy storage device is added and the energy storage control strategy simply considers the distribution transformer loss.

[0050] Figure 8 This is a schematic diagram of the energy storage output power curve when an energy storage device is added and the energy storage control strategy simply considers the distribution transformer loss in the embodiment of the method of the present invention.

[0051] Figure 9 This is a schematic diagram of the apparent power and energy storage output curve of the distribution transformer when an energy storage device is added and the energy storage control strategy is in accordance with the solution of the present application according to the method embodiment of the present invention.

[0052] Figure 10 This is a schematic diagram of the actual power curve of the distribution transformer in which an energy storage device is added and the energy storage control strategy is in accordance with the solution of this application according to the method embodiment of the present invention.

[0053] Figure 11 This is a schematic diagram of the energy storage output power curve when an energy storage device is added to the method embodiment of the present invention and the energy storage control strategy is in accordance with the solution of this application.

[0054] Figure 12 Schematic diagram of the functional modules of the system of the present invention. DETAILED DESCRIPTION

[0055] like Figure 1 The figure shows a schematic flow chart of the method of the present invention: The distributed energy storage control method considering distribution transformer loss disclosed in the present invention comprises the following steps:

[0056] S1. Obtain historical data information of the target power system.

[0057] S2. Based on the data information obtained in step S1, the comprehensive power economic load factor of the distribution transformer and the corresponding optimal economic operating range are calculated based on the active no-load loss, active short-circuit loss and load fluctuation loss of the distribution transformer; specifically comprising the following steps:

[0058] The operating losses of a distribution transformer mainly come from its internal iron loss and copper loss. When the output of the distribution transformer is zero, its efficiency is also zero; when the output of the distribution transformer increases, the efficiency first increases and then decreases; therefore, controlling the output of the distribution transformer within a reasonable range can effectively improve its operating efficiency; when the distribution transformer is under heavy load or even overload, its internal temperature rise will increase the coil resistance, and the copper loss will increase, and the performance of the insulation material will decrease. In severe cases, it will cause the relevant materials to lose their insulation properties, affecting the safe and stable operation of the distribution transformer and causing irreversible damage to the equipment; it can be seen that controlling the load rate of the distribution transformer within a reasonable range can improve the safety of its operation.

[0059] The load factor of the distribution transformer is the ratio of the apparent power output of the distribution transformer to the rated capacity of the transformer over a period of time, expressed as: In the formula is the actual apparent power of the distribution transformer over a period of time, is the actual active power of the distribution transformer over a period of time, To show the actual power factor of the distribution transformer over a period of time;

[0060] Operating losses of distribution transformers , including active loss and reactive loss, expressed as: In the formula is the active no-load loss of the distribution transformer; is the reactive economic equivalent of the distribution transformer; is the reactive no-load loss of the distribution transformer; The load fluctuation loss coefficient of the distribution transformer indicates the ratio of the load loss of the distribution transformer under load fluctuation conditions to the load loss under average load conditions within a certain period of time. Due to the fluctuation of the distribution transformer load, this coefficient is introduced to correct the calculation result using the average load coefficient. is the active short-circuit loss of the distribution transformer; is the reactive short-circuit loss of the distribution transformer;

[0061] because The general value is very small (about 0.04), and the influence of reactive power loss can be reduced by reactive power compensation. Therefore, in the calculation process, the loss effect caused by reactive power can be ignored, and only active power loss is calculated, so we can get .

[0062] Active power on the power supply side of the distribution transformer Equal to the load side active power of the distribution transformer, that is, the actual active power of the distribution transformer Adding the operating loss of the distribution transformer, it is expressed as ;

[0063] Comprehensive loss rate of distribution transformer Expressed as: After ignoring the reactive component, the power factor of the distribution transformer is also considered to be approximately equal to 1, then the comprehensive loss rate of the distribution transformer can be expressed as In addition, since the data acquisition frequency is generally high (reaching 50kHz or above) in the control strategy of the distributed energy storage system, the load loss fluctuation coefficient can be approximately considered to be equal to 1, thus obtaining ;

[0064] It can be seen that the comprehensive loss rate of the distribution transformer shows a nonlinear change with the load factor, and the function approaches the maximum value of 1. As the load factor increases, the comprehensive power loss rate is a curve that first decreases and then increases (such as Figure 2 As shown in the figure, the lowest point is the comprehensive power economic load factor, indicating that under this load factor, the comprehensive power loss rate of the transformer is the lowest and the operation is the most economical. At this time, the iron loss of the transformer is the same as the copper loss, so the comprehensive power economic load factor of the distribution transformer is calculated using the following formula: : In the formula is the active no-load loss of the distribution transformer; is the load fluctuation loss coefficient of the distribution transformer; is the active short-circuit loss of the distribution transformer;

[0065] According to the national standard GB / T 13462-2008 "Economic Operation of Power Transformers" 6.1.3, the division of the best economic operation zone shows that the distribution transformer is operated at 75% load as the upper limit of the best economic operation zone, and the other point with the same comprehensive power loss rate as the upper limit of the best economic operation zone is the lower limit of the best operation zone. Therefore, the upper limit load factor of the best economic operation range of the distribution transformer is obtained. The lower limit load factor of the optimal economic operation range of the distribution transformer is 0.75. for .

[0066] S3. Based on several days of historical distribution transformer load data, obtain statistical data on the time periods when the distribution transformer load rate was above and below the optimal economic operating range. This specifically includes the following steps:

[0067] Obtain the load rate data of the distribution transformer within the historical T days, set the daily load sampling points to N, and the load rate curve of the historical day j is Expressed as , is the load rate of the distribution transformer at the i-th sampling point on the j-th day in history, , ;

[0068] According to the load rate curve of the distribution transformer, the load rate of the distribution transformer in the historical T days is greater than the upper limit load factor of the optimal economic operation range. The number of sampling points , and the load factor of the distribution transformer in the history of T days is less than the lower limit load factor of the optimal economic operation range The number of sampling points .

[0069] S4 according to the time data obtained in step S3, the distribution transformer load rate is statistically obtained when the power data is higher and lower than the optimal economic operating range; specifically comprising the following steps:

[0070] According to the time data obtained in step S3, the power data when the load rate of the distribution transformer is higher than the optimal economic operation range is calculated. : According to the time data obtained in step S3, the power data when the load rate of the distribution transformer is lower than the optimal economic operation range is calculated. : In the formula is the rated capacity of the distribution transformer.

[0071] S5. Based on the relationship between the power data obtained in step S4 when the distribution transformer load factor is higher than the optimal economic operating range and the power data when the distribution transformer load factor is lower than the optimal economic operating range, and based on the comprehensive power economic load factor of the distribution transformer, the power data, and the time data, set the discharge threshold, charging threshold, and output power of the distributed energy storage.

[0072] The specific implementation includes the following steps:

[0073] If the power data and power data If the values ​​are equal, the charge and discharge thresholds of the distributed energy storage system on the substation side are set to the upper and lower load factors of the optimal economic operation zone of the distribution transformer, and the distribution transformer is set to operate in the optimal economic operation zone;

[0074] If the power data Greater than power data , then the charge and discharge thresholds of the distributed energy storage system on the substation side are set to the upper and lower limit load factors of the optimal economic operation zone of the distribution transformer. At this time, the discharge capacity of the distributed energy storage system on the substation side is greater than the charge capacity of the energy storage. Therefore, it is necessary to simultaneously increase the charge capacity of the distributed energy storage system on the substation side during the low period of the distribution network;

[0075] If the power data Less than power data , the charge and discharge thresholds of the distributed energy storage system on the substation side are set to the upper and lower limit load factors of the optimal economic operation zone of the distribution transformer. At this time, the discharge capacity of the distributed energy storage system on the substation side is less than the charge capacity of the energy storage. Therefore, it is necessary to simultaneously increase the discharge capacity of the distributed energy storage system on the substation side during the peak period of the distribution network.

[0076] Specifically, when the power data and power data Equal, use the following steps to set up distributed energy storage:

[0077] Set the discharge threshold of the distributed energy storage system to ;

[0078] Set the charging threshold of the distributed energy storage system to ;

[0079] Set the output power of the distributed energy storage system for Where is the real-time load rate of the distribution transformer at time t in the future;

[0080] At this time, the load rate curve of the optimized distribution transformer is for .

[0081] When power data Greater than power data When using distributed energy storage, use the following steps to set up distributed energy storage:

[0082] Set the discharge threshold of the distributed energy storage system to ;

[0083] Set the charging threshold of the distributed energy storage system to ;

[0084] Set the output power of the distributed energy storage system for ;

[0085] At this time, the load rate curve of the optimized distribution transformer is for .

[0086] When power data Less than power data When using distributed energy storage, use the following steps to set up distributed energy storage:

[0087] Set the discharge threshold of the distributed energy storage system to ;

[0088] Set the charging threshold of the distributed energy storage system to ;

[0089] Set the output power of the distributed energy storage system for ; is the real-time load rate of the distribution transformer at time t in the future.

[0090] At this time, the load rate curve of the optimized distribution transformer is for .

[0091] The above output power of distributed energy storage system , mainly based on 0.75 and Based on the data, and supplemented by the deviation of historical charge and discharge amounts as correction.

[0092] S6. Complete the control of the distributed energy storage of the target power system according to the discharge threshold, charge threshold, and output power of the distributed energy storage set in step S5.

[0093] The method of the present invention is described below with reference to an embodiment:

[0094] An actual distribution transformer in Hunan Province is selected. The name of the distribution transformer is NG320550 Liquan I line Changqiao 2nd group, located in Xiangxiang City, Xiangtan City, Hunan Province. The total capacity of the distribution transformer is 100 kVA, and it is S11 model. After checking the nameplate parameters of the distribution transformer, it can be known that the no-load loss of the distribution transformer is 200W, active short-circuit loss is 1500 watts, assuming the load fluctuation loss factor of the distribution transformer is =0, the comprehensive power economic load factor of the distribution transformer is calculated for: That is, the comprehensive loss rate of the distribution transformer is the smallest when the load rate is 36.5%; the upper limit load factor of the optimal economic operation range of the distribution transformer is 0.75, and the lower limit load of the optimal economic operation range of the distribution transformer is 0.177.

[0095] The load condition of the distribution transformer from January 24, 2025 to February 5, 2025 is retrieved, and a point is collected every 15 minutes. The apparent power of the distribution transformer is as follows: Figure 3 shown.

[0096] Case 1-without energy storage device:

[0097] If the energy storage device is not installed, the peak-to-valley difference of the distribution transformer is large, and the distribution transformer is overloaded in certain periods (i.e. the distribution transformer load rate is greater than 80%). The specific curve is as follows Figure 4 shown.

[0098] Case 2 - Energy storage device is installed, and the energy storage control strategy does not consider the distribution transformer loss:

[0099] If a 30kW / 60kWh energy storage device is installed, the control strategy without considering the distribution transformer loss is adopted, that is, the energy storage device starts discharging when the distribution transformer load rate is greater than 80%, and maintains the distribution transformer load rate at 80% during discharging; it starts charging when the distribution transformer load rate is lower than 80% of the discharge threshold, that is, the distribution transformer load rate is lower than 64%, and maintains the distribution transformer load rate at 64% during charging.

[0100] After the energy storage device was installed, the load of the distribution transformer was peak-loaded and valley-filled. Figure 5 and Figure 6 It can be seen that the distribution transformer has no heavy load range higher than 80% load factor. In this case, the distribution transformer loss is reduced.

[0101] Case 3 - Energy storage device is installed, and the energy storage control strategy simply considers the distribution transformer loss:

[0102] A 30kW / 60kWh energy storage device is installed, and the control strategy for the distribution transformer loss is simply considered. That is, the energy storage device starts discharging when the distribution transformer load rate is greater than 75%, and maintains the distribution transformer load rate at 75% during discharge; it starts charging when the distribution transformer load rate is lower than 17.7%, and maintains the distribution transformer load rate at 17.7% during charging. The specific curve is as follows Figure 7 and Figure 8 shown.

[0103] Case 4 - Installing an energy storage device, the energy storage control strategy follows the control algorithm of this patent:

[0104] A 30kW / 60kWh energy storage device is installed. Considering the control strategy of distribution transformer loss, the patented control algorithm is adopted. The energy storage device starts discharging when the distribution transformer load rate is greater than 75%, and maintains the distribution transformer load rate at 75% during discharge; it starts charging when the distribution transformer load rate is less than 17.7%, and maintains the distribution transformer load rate at 17.7% during charging. The load situation of the three historical days is calculated to obtain the power data when the distribution transformer load rate is higher than the optimal economic operation range. The power data when the load rate of the distribution transformer is lower than the optimal economic operation range is 85.89 kilowatts. The discharge capacity of the distributed energy storage system on the substation side is 209.57 kilowatts, which is less than the charging capacity of the energy storage. It is necessary to increase the discharge capacity of the distributed energy storage system on the substation side during the peak of the distribution network. The specific curve is as follows: Figure 9 shown.

[0105] There are 14 moments in the discharge state, so the energy storage control strategy is adjusted so that the discharge threshold and charge threshold remain at 75% and 17.7% load rate, and the discharge / charge control values ​​are 66.17% and 17.7%, respectively. The specific curves are as follows: Figure 10 and Figure 11 shown.

[0106] The average distribution transformer loss rate under the four conditions is shown in Table 1 below:

[0107] Table 1 Schematic diagram of average distribution transformer loss rate

[0108]

[0109] pass Figures 4 to 11 As can be seen from Table 1, the solution of the present invention can not only effectively solve the problem of heavy overload of the distribution transformer, but also fully consider the comprehensive loss rate of the distribution transformer; compared with the traditional solution and the solution that simply considers the distribution transformer loss, the solution of the present invention can further reduce the average loss rate of the distribution transformer, so that the energy storage device can achieve economical, coordinated and efficient operation with the distribution transformer after being connected to the distribution transformer.

[0110] like Figure 12The figure shows a functional module diagram of the system of the present invention: the system disclosed in the present invention for realizing the distributed energy storage control method considering distribution transformer loss comprises a data acquisition module, a first calculation module, a time statistics module, a power statistics module, a parameter setting module and an energy storage control module; the data acquisition module, the first calculation module, the time statistics module, the power statistics module, the parameter setting module and the energy storage control module are connected in series in sequence; the data acquisition module is used to acquire historical data information of the target power system and upload the data information to the first calculation module; the first calculation module is used to calculate the comprehensive power economic load factor of the distribution transformer and the corresponding optimal economic operation range based on the active no-load loss, active short-circuit loss and load fluctuation loss of the distribution transformer according to the received data information, and upload the data information to the time statistics module; the time statistics module is used to obtain the distribution transformer load data of several days according to the received data information. The power statistics module is used to obtain the time data of the distribution transformer load rate being higher and lower than the optimal economic operation range according to the received data information and the obtained time data, and upload the data information to the power statistics module; the power statistics module is used to obtain the power data when the distribution transformer load rate is higher and lower than the optimal economic operation range according to the received data information and the obtained time data, and upload the data information to the parameter setting module; the parameter setting module is used to set the discharge threshold, charging threshold and output power of the distributed energy storage based on the received data information and the relationship between the power data when the distribution transformer load rate is higher than the optimal economic operation range and the power data when the distribution transformer load rate is lower than the optimal economic operation range, based on the comprehensive power economic load coefficient, power data and time data of the distribution transformer, and upload the data information to the energy storage control module; the energy storage control module is used to complete the control of the distributed energy storage of the target power system according to the received data information and the set discharge threshold, charging threshold and output power of the distributed energy storage.

Claims

1. A distributed energy storage control method considering distribution transformer losses, characterized in that The steps include: S1. Obtain historical data information of the target power system; S2. According to the data information obtained in step S1, based on the active no-load loss, active short-circuit loss and load fluctuation loss of the distribution transformer, the comprehensive power economic load factor of the distribution transformer and the corresponding optimal economic operation range are calculated; S3. Based on several days of historical distribution transformer load data, obtain statistical data on the time periods when the distribution transformer load factor was above and below the optimal economic operating range; S4 according to the time data obtained in step S3, the distribution transformer load rate is statistically obtained when the power data is higher and lower than the optimal economic operating range; S5. According to the relationship between the power data when the distribution transformer load rate is higher than the optimal economic operating range and the power data when the distribution transformer load rate is lower than the optimal economic operating range obtained in step S4, the discharge threshold, charging threshold and output power of the distributed energy storage are set based on the comprehensive power economic load factor of the distribution transformer, power data and time data; S6. Complete the control of the distributed energy storage of the target power system according to the discharge threshold, charge threshold, and output power of the distributed energy storage set in step S5.

2. The distributed energy storage control method considering distribution transformer loss according to claim 1 is characterized in that The step S2 specifically includes the following steps: The comprehensive power economic load factor of the distribution transformer is calculated using the following formula: : In the formula is the active no-load loss of the distribution transformer; is the load fluctuation loss coefficient of the distribution transformer; is the active short-circuit loss of the distribution transformer; Since the distribution transformer is operated at 75% load as the upper limit of the optimal economic operation zone, and the other point with the same comprehensive power loss rate as the upper limit of the optimal economic operation zone is the lower limit of the optimal operation zone, the upper limit load factor of the optimal economic operation range of the distribution transformer is obtained. The lower limit load factor of the optimal economic operation range of the distribution transformer is 0.

75. for .

3. The distributed energy storage control method considering distribution transformer loss according to claim 2 is characterized in that The step S3 specifically includes the following steps: Obtain the load rate data of the distribution transformer within the historical T days, set the daily load sampling points to N, and the load rate curve of the historical day j is Expressed as , is the load rate of the distribution transformer at the i-th sampling point on the j-th day in history, , ; According to the load rate curve of the distribution transformer, the load rate of the distribution transformer in the historical T days is greater than the upper limit load factor of the optimal economic operation range. The number of sampling points , and the load factor of the distribution transformer in the history of T days is less than the lower limit load factor of the optimal economic operation range The number of sampling points .

4. The distributed energy storage control method considering distribution transformer loss according to claim 3 is characterized in that The step S4 specifically includes the following steps: According to the time data obtained in step S3, the power data when the load rate of the distribution transformer is higher than the optimal economic operation range is calculated. : According to the time data obtained in step S3, the power data when the load rate of the distribution transformer is lower than the optimal economic operation range is calculated. : In the formula is the rated capacity of the distribution transformer.

5. The distributed energy storage control method considering distribution transformer loss according to claim 4 is characterized in that The step S5 comprises the following steps: If the power data and power data If the values ​​are equal, the charge and discharge thresholds of the distributed energy storage system on the substation side are set to the upper and lower load factors of the optimal economic operation zone of the distribution transformer, and the distribution transformer is set to operate in the optimal economic operation zone; If the power data Greater than power data , then the charge and discharge thresholds of the distributed energy storage system on the substation side are set to the upper and lower limit load factors of the optimal economic operation zone of the distribution transformer, and the charging capacity of the distributed energy storage system on the substation side is increased when the distribution network is off; If the power data Less than power data , the charge and discharge thresholds of the distributed energy storage system on the substation side are set to the upper and lower limit load factors of the optimal economic operation zone of the distribution transformer, and the discharge capacity of the distributed energy storage system on the substation side is increased during the peak period of the distribution network.

6. The distributed energy storage control method considering distribution transformer loss according to claim 5 is characterized in that When power data and power data Equal, use the following steps to set up distributed energy storage: Set the discharge threshold of the distributed energy storage system to ; Set the charging threshold of the distributed energy storage system to ; Set the output power of the distributed energy storage system for Where is the real-time load rate of the distribution transformer at time t in the future; At this time, the load rate curve of the optimized distribution transformer is for 。 7. The distributed energy storage control method considering distribution transformer loss according to claim 5 is characterized in that When power data Greater than power data When using distributed energy storage, use the following steps to set up distributed energy storage: Set the discharge threshold of the distributed energy storage system to ; Set the charging threshold of the distributed energy storage system to ; Set the output power of the distributed energy storage system for ； At this time, the load rate curve of the optimized distribution transformer is for 。 8. The distributed energy storage control method considering distribution transformer loss according to claim 5 is characterized in that When power data Less than power data When using distributed energy storage, use the following steps to set up distributed energy storage: Set the discharge threshold of the distributed energy storage system to ; Set the charging threshold of the distributed energy storage system to ; Set the output power of the distributed energy storage system for ； At this time, the load rate curve of the optimized distribution transformer is for 。 9. A system for implementing the distributed energy storage control method considering distribution transformer loss according to any one of claims 1 to 8, characterized in that The system comprises a data acquisition module, a first calculation module, a time statistics module, a power statistics module, a parameter setting module and an energy storage control module; the data acquisition module, the first calculation module, the time statistics module, the power statistics module, the parameter setting module and the energy storage control module are connected in series in sequence; the data acquisition module is used to obtain historical data information of the target power system and upload the data information to the first calculation module; the first calculation module is used to calculate the comprehensive power economic load factor of the distribution transformer and the corresponding optimal economic operation range based on the active no-load loss, active short-circuit loss and load fluctuation loss of the distribution transformer according to the received data information, and upload the data information to the time statistics module; the time statistics module is used to calculate the comprehensive power economic load factor of the distribution transformer and the corresponding optimal economic operation range based on the received data information and the acquired data information, based on the active no-load loss, active short-circuit loss and load fluctuation loss of the distribution transformer, and upload the data information to the time statistics module; the time statistics module is used to calculate the comprehensive power economic load factor of the distribution transformer and the corresponding optimal economic operation range based on the received data information and the distribution transformer load data of several historical days According to the received data information, the time data of when the load rate of the distribution transformer is higher than and lower than the optimal economic operation range is obtained by statistics, and the data information is uploaded to the power statistics module; the power statistics module is used to obtain the power data when the load rate of the distribution transformer is higher than and lower than the optimal economic operation range according to the received data information and the obtained time data, and upload the data information to the parameter setting module; the parameter setting module is used to set the discharge threshold, charging threshold and output power of the distributed energy storage based on the comprehensive power economic load coefficient, power data and time data of the distribution transformer according to the received data information and the relationship between the power data when the load rate of the distribution transformer is higher than the optimal economic operation range and the power data when the load rate of the distribution transformer is lower than the optimal economic operation range, and upload the data information to the energy storage control module; The energy storage control module is used to complete the control of the distributed energy storage of the target power system according to the received data information and the set discharge threshold, charging threshold and output power of the distributed energy storage.

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