A method and system for controlling coordinated power support in substations

Abstract

The present invention relates to a method and system for coordinated power support control of a substation, in the field of power distribution automation, the method includes unit support control within the substation and coordinated control between substations; the unit support control within the substation includes the following steps: step 1: distributed photovoltaic and load power prediction; (1) determining index calculation factors; the index calculation factors include: load prediction factors and photovoltaic prediction factors; (2) data normalization processing; (3) data preprocessing; (4) grey system modeling prediction; (5) inverse normalization of prediction results; step 2: distributed photovoltaic support control; step 3: energy storage system regulation control; coordinated control between substations includes converting the coordinated control between substations of the distribution network into the upper / lower limit control of maximizing the dynamic load of the distribution network. The present invention solves the problem of coordinated power support control of substations and improves the energy utilization efficiency, stability and sustainable development level of the power system and the distribution network.

Description

Technical Field

[0001] The present invention relates to the field of power distribution automation, and in particular to a method and system for controlling coordinated power support of power distribution areas. Background Art

[0002] The large-scale and intensive grid connection of distributed power sources has led to frequent voltage fluctuations in the substation area and large-scale power reverse transmission problems, which has increased the difficulty of distribution network operation and control, reduced the system's ability to accept distributed photovoltaics, and posed problems to the safe, stable and economical operation of the distribution network.

[0003] At different time scales, the degree of fluctuation of photovoltaic output varies. The regulation potential and regulation characteristics of distributed photovoltaic and traditional system control devices are very different. In terms of spatial distribution, distributed photovoltaics are connected to the power grid in a large number of dispersed ways, causing some distribution substations to face the problem of source-load mismatch.

[0004] Through the interconnection of source-load differentiated substations, it is helpful to solve the problems of local consumption and grid security and stability after large-scale distributed photovoltaic access. However, the network topology of the multi-substation Internet system is complex and the operation mode is diverse. Therefore, it is necessary to solve the problem of substation coordinated power support control to improve the energy utilization efficiency, stability and sustainable development level of the power system and distribution network. Summary of the invention

[0005] The purpose of the present invention is to provide a coordinated power support control method and system for power distribution areas, so as to solve the problem of source-load mismatch in some distribution areas caused by the large-scale decentralized access of distributed photovoltaic power generation to the power grid.

[0006] A coordinated power support control method for a substation, the method comprising intra-substation unit support control and inter-substation coordinated control;

[0007] The unit support control in the station area includes the following steps:

[0008] Step 1: Distributed photovoltaic and load power forecast;

[0009] (1) Determine the index calculation factors; the index calculation factors include: load prediction factor and photovoltaic prediction factor;

[0010] (2) Data normalization;

[0011] (3) Data preprocessing;

[0012] (4) Grey system modeling and prediction;

[0013] (5) Denormalization of prediction results;

[0014] Step 2: Distributed photovoltaic support control;

[0015] Step 3: Energy storage system regulation and control.

[0016] The coordinated control between substations includes the following steps: coordination among multiple resources such as source, load and storage, and the conversion of the coordinated control between substations of the distribution network into the upper / lower limit control that maximizes the dynamic load of the distribution network.

[0017] Preferably, in step 1, the load prediction factor includes the load active power factor and the load reactive power factor: extract the historical load data at point F every day, where F is an integer, and the load active power factor includes the load active power of the week, time, and one hour before the current moment; the load reactive power factor includes the load reactive power of the week, time, and one hour before the current moment;

[0018] Photovoltaic prediction factors, including photovoltaic power factor: extract historical photovoltaic power data at daily F point. Photovoltaic power factor includes: time, photovoltaic capacity, photovoltaic active power, photovoltaic reactive power, and photovoltaic power data one hour before the current time.

[0019] Preferably, the data normalization process includes: normalizing the indicator calculation factors; the normalization process uses one or more of a positive indicator, an interval indicator or a reverse indicator;

[0020] Normalization formula for positive indicators:

[0021] ,

[0022] In the formula, , They are the maximum and minimum values ​​of the index calculation factors in several low-voltage distribution substations. is the actual value of the indicator calculation factor, is the normalized value of the indicator calculation factor, i is the number of indicator calculation factors and is an integer;

[0023] The normalization formula of interval indicators is:

[0024] ,

[0025] In the formula, The middle value of the interval for calculating the indicator factor, optionally, , max means taking the maximum value;

[0026] Reverse indicator normalization processing formula:

[0027] .

[0028] Preferably, in step 1, data preprocessing includes:

[0029] The original data normalized by the indicator calculation factor Accumulation processing weakens the volatility and randomness of the random sequence and obtains accumulated data ,in Respectively represent the normalized values ​​of the indicator calculation factors The 0th, 1st, ..., F-1th sampling point data,

[0030] ,

[0031] Wherein, k is an integer.

[0032] Preferably, the grey system modeling prediction includes: the grey system model is:

[0033] ,

[0034] in, Indicates the value of the cumulative generated sequence, It represents the sequence of the average values ​​of the immediately adjacent sequences generated by accumulation. and are the least squares coefficients respectively, N is the number of index calculation factors, ;

[0035] Using the least squares method The indicator calculation factor value y at time t is predicted and output.

[0036] Preferably, the result inverse normalization comprises:

[0037] The index calculation factors are taken as photovoltaic active power and load active power, and the predicted output solved by the grey system model is inversely normalized to obtain the actual photovoltaic active power value. and load power value , load power value Included and , and They are i The active load power and reactive load power connected to the node.

[0038] Preferably, steps 2 and 3 further include:

[0039] Step 2: Distributed photovoltaic support control;

[0040] The photovoltaic active power adjustment range is , the photovoltaic reactive power adjustment range is , PF is the power factor;

[0041] Step 3: Energy storage system regulation and control;

[0042] Energy storage system power The output adjustment range is: ,in is the maximum discharge power, The maximum charging power;

[0043] In order to ensure the continuity of energy storage output power, the capacity constraint of the SOC of the energy storage system is checked within the output power range. The formula is:

[0044] ,

[0045] ,

[0046] is the current SOC value of the energy storage system, For charging efficiency, is the discharge efficiency, is the capacity of the energy storage system, is the current power value of the energy storage system, For the time interval.

[0047] Preferably, the inter-station coordinated control further includes: the inter-station coordinated control of the distribution network is converted into the upper / lower limit control of maximizing the dynamic load of the distribution network, including:

[0048] ,

[0049] in, for t The upper limit power carried by the distribution network feeder at any moment, for t The total power of load and energy storage in the distribution network at time h, R is the number of distribution network areas;

[0050] Constraints include: power transmission constraints of transformers in the substation area, power flow constraints, and alert power quality constraints;

[0051] Transformer power transmission constraints in the substation area:

[0052] ,

[0053] in, for t The distributed photovoltaic power generation power in the distribution network area h at the moment, , is the upper and lower limits of the transmission power of the transformer in the distribution network area h; optionally, the area corresponds to the node;

[0054] The power flow equation for power flow constraint is:

[0055] ,

[0056] in, is the set of end nodes of the distribution network branch, γ ( i ) is the set of first nodes of distribution network branches; , , are the branch resistance, reactance and current between node i and node j respectively; and are the active power and reactive power transmitted between node i and node j respectively; and are the node voltages of node i and node j respectively; , They are i The active output and reactive output of the distributed power sources connected to the node; and They are i The charging and discharging power of the energy storage to which the node is connected; , for i The node can interrupt the load active power and reactive power;

[0057] The warning power quality constraints limit the average voltage deviation of all distribution network sections to within the preset limit range.

[0058] A substation coordinated power support control system, the system includes distributed photovoltaic, energy storage system, load and substation, the distributed photovoltaic, energy storage system, load and substation are connected through a distribution network; the distribution network includes power equipment and feeder lines; there are multiple distributed photovoltaic as power sources, there are multiple substations distributed in the distribution network, multiple power loads are distributed in the distribution network and each substation, one or more energy storage systems are arranged at one or more nodes of the distribution network, and distributed photovoltaic as a power source is connected to the power grid through different substations.

[0059] A computer storage medium comprises a memory, a processor and a computer program stored in the memory and executable by the processor, wherein the processor implements a method for coordinated power support control of a substation when executing the computer program.

[0060] Beneficial effects:

[0061] Through coordinated power support control among substations, the coordinated support capabilities among different substations are better balanced, and the interconnection construction and operation mode of substations are optimized; the optimization of the upper limit power carried by the distribution network feeder realizes the load balance among substations, power supply scheduling and optimized scheduling of feeder fault recovery, which is helpful to optimize the grid structure of the distribution network, promote the use of smart grid and photovoltaic new energy technologies, and improve the energy utilization efficiency, stability and sustainable development level of the power system and distribution network. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 It is a schematic diagram of a coordinated power support control method for a substation area according to an embodiment of the present invention.

[0063] Figure 2 Schematic diagram of distributed photovoltaic and load power prediction according to an embodiment of the present invention

[0064] Figure 3 Schematic diagram of the computer storage medium structure according to an embodiment of the present invention. DETAILED DESCRIPTION

[0065] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0066] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0067] Example 1

[0068] like Figure 1 , Figure 2 The present invention aims at the coordinated control and application scenarios of power supply substations and proposes a method and system for coordinated power support control of substations.

[0069] The substation collaborative power support control system includes distributed photovoltaics, energy storage systems, loads and substations, and the distributed photovoltaics, energy storage systems, loads and substations are connected through a power grid; optionally, the power grid includes power equipment and feeder lines; optionally, there are multiple distributed photovoltaics as power sources, there are multiple substations distributed in the power grid, multiple power loads are distributed in the power grid and each substation, one or more energy storage systems are arranged at one or more nodes of the power grid and the nodes may be the same or different, and the distributed photovoltaics are connected to the power grid through different substations as a power source.

[0070] The coordinated power support control method of the substation includes intra-substation unit support control and inter-substation coordinated control.

[0071] The unit support control in the station area includes the following steps:

[0072] The distribution network has multiple evaluation indicators; the evaluation indicators include power supply and demand balance indicators, load regulation indicators, power generation regulation indicators and reactive power regulation indicators.

[0073] Power supply and demand balance indicators include the balance between power generation and load demand, average power supply rate and peak-to-valley difference.

[0074] Load regulation indicators include load regulation index and load regulation time.

[0075] The power generation regulation indicators include the power generation regulation index and the power generation regulation time.

[0076] Reactive power regulation indicators include reactive power compensation rate and reactive power regulation time.

[0077] Step 1: Distributed PV and load power forecasting.

[0078] (1) Determine the indicator calculation factors.

[0079] The index calculation factors include: load prediction factor and photovoltaic prediction factor.

[0080] Load prediction factors, including load active power factor and load reactive power factor: extract historical load data at point F every day, where F is an integer. Load active power factor includes the day of the week, time, and load active power one hour before the current moment; load reactive power factor includes the day of the week, time, and load reactive power one hour before the current moment.

[0081] Optionally, the historical load is extracted for 96 points of data every day, and the load active power factor includes the day of the week (0-6, 0 for Sunday, 1 for Monday, 2 for Tuesday, 3 for Wednesday, 4 for Thursday, 5 for Friday, and 6 for Saturday), time (0-95, 0 for the 0th moment, 1 for the 1st moment, 2 for the 2nd moment, ..., 95 for the 95th moment), and the load active power data one hour before the current moment; the load reactive power factor includes the day of the week (0-6, 0 for Sunday, 1 for Monday, 2 for Tuesday, 3 for Wednesday, 4 for Thursday, 5 for Friday, and 6 for Saturday), time (0-95, 0 for the 0th moment, 1 for the 1st moment, 2 for the 2nd moment, ..., 95 for the 95th moment), and the load reactive power data one hour before the current moment.

[0082] Photovoltaic prediction factors, including photovoltaic power factor: extract historical photovoltaic power data at daily F point. Photovoltaic power factor includes: time, photovoltaic capacity, photovoltaic active power, photovoltaic reactive power, and photovoltaic power data one hour before the current time.

[0083] Optionally, historical photovoltaic data is extracted at 96 points every day, and the photovoltaic power factor includes time (0-95, 0 represents the 0th moment, 1 represents the 1st moment, 2 represents the 2nd moment, ..., 95 represents the 95th moment), photovoltaic capacity, photovoltaic active power, photovoltaic reactive power, and photovoltaic power data 1 hour before the current moment.

[0084] (2) Data normalization processing.

[0085] The indicator calculation factors are normalized to ensure the comparability and consistency of the data.

[0086] Normalization formula for positive indicators:

[0087] ,

[0088] In the formula, , They are the maximum and minimum values ​​of the index calculation factors in several low-voltage distribution substations. is the actual value of the indicator calculation factor, is the normalized value of the indicator calculation factor, i is the number of indicator calculation factors and is an integer.

[0089] The normalization formula of interval indicators is:

[0090] ,

[0091] In the formula, The middle value of the interval for calculating the indicator factor, optionally, , max means taking the maximum value.

[0092] Reverse indicator normalization processing formula:

[0093] ,

[0094] (3) Data preprocessing;

[0095] The original data normalized by the indicator calculation factor Accumulation processing weakens the volatility and randomness of the random sequence and obtains accumulated data ,in Respectively represent the normalized values ​​of the indicator calculation factors The 0th, 1st, ..., F-1th sampling point data,

[0096] ,

[0097] Wherein, k is an integer;

[0098] (4) Grey system modeling and prediction;

[0099] The grey system model is:

[0100] ,

[0101] in, Indicates the value of the cumulative generated sequence, It represents the sequence of the average values ​​of the immediately adjacent sequences generated by accumulation. and are the least squares coefficients respectively, N is the number of index calculation factors, .

[0102] Using the least squares method The indicator calculation factor value y at time t is predicted and output.

[0103] (5) The results are reverse normalized;

[0104] The index calculation factors are taken as photovoltaic active power and load active power, and the predicted output solved by the grey system model is inversely normalized to obtain the actual photovoltaic active power value. and load power value , load power value Included and , and They are i The active load power and reactive load power connected to the node.

[0105] Step 2: Distributed photovoltaic support control.

[0106] The photovoltaic active power adjustment range is , the photovoltaic reactive power adjustment range is , PF is the power factor.

[0107] Step 3: Energy storage system regulation and control.

[0108] Energy storage system power The output adjustment range is: ,in is the maximum discharge power, is the maximum charging power; to ensure the continuity of the energy storage output power, the capacity constraint check of the SOC of the energy storage system is carried out within the output power range. The formula is:

[0109] ,

[0110] ,

[0111] is the current SOC value of the energy storage system, For charging efficiency, is the discharge efficiency, is the capacity of the energy storage system, is the current power value of the energy storage system, For the time interval.

[0112] The coordinated control between stations is as follows:

[0113] After clarifying the self-regulation potential corresponding to the adjustable resources in the distribution network in units of substations, considering the coordination among multiple resources of source, load and storage and the cooperation among controllable reactive equipment, the inter-substation coordinated control of the distribution network in the region is converted into the upper / lower limit control that maximizes the dynamic load of the distribution network:

[0114] ,

[0115] in, for t The upper limit power carried by the distribution network feeder at any moment, for t The total power of load and energy storage in the distribution network at time h, R is the number of distribution network substations. The constraints include: substation transformer power transmission constraints, power flow constraints and warning power quality constraints.

[0116] Transformer power transmission constraints in the substation area:

[0117] ,

[0118] in, for t The distributed photovoltaic power generation power in the distribution network area h at the moment, , are the upper and lower limits of the transmission power of the transformer in the distribution network area h; optionally, the area corresponds to the node.

[0119] The power flow equation for power flow constraint is:

[0120] ,

[0121] in, is the set of end nodes of the distribution network branch, γ ( i ) is the set of first nodes of distribution network branches; , , are the branch resistance, reactance and current between node i and node j respectively; and are the active power and reactive power transmitted between node i and node j respectively; and are the node voltages of node i and node j respectively; , They are i The active output and reactive output of the distributed power sources connected to the node; and They are i The charging and discharging power of the energy storage to which the node is connected; , for i The node can interrupt the load active power and reactive power.

[0122] The warning power quality constraints limit the average voltage deviation of all substations in the distribution network to a preset limit range. Optionally, the preset limit is (-5%, +5%), (-7%, +7%), (-5%, +7%) or (-7%, +5%).

[0123] Through coordinated power support control among substations, the coordinated support capabilities among different substations are better balanced, and the interconnection construction and operation mode of substations are optimized; the optimization of the upper limit power carried by the distribution network feeder realizes the load balance among substations, power supply scheduling and optimized scheduling of feeder fault recovery, which is helpful to optimize the grid structure of the distribution network, promote the use of smart grid and photovoltaic new energy technologies, and improve the energy utilization efficiency, stability and sustainable development level of the power system and distribution network.

[0124] Example 2

[0125] This embodiment is based on Embodiment 1, and the difference between this embodiment and Embodiment 1 is that:

[0126] (2) In the step of data normalization, the index calculation factors are taken as the PV active power and the load active power. Considering that the PV active power is a positive value greater than the minimum value of the PV active power, the PV active power is processed using the reverse index normalization formula:

[0127] ,

[0128] Considering the large fluctuation of load active power, in order to smooth the load fluctuation rate, the load active power is processed using the interval index normalization formula:

[0129]

[0130] In the formula, is the middle value of the load active power interval, optionally, , max means taking the maximum value.

[0131] (3) Data preprocessing;

[0132] Normalized raw data of PV active power and load active power Accumulation processing weakens the volatility and randomness of the random sequence and obtains accumulated data ,in Represents the normalized values ​​of PV active power and load active power respectively The 0th, 1st, ..., F-1th sampling point data,

[0133] ,

[0134] Wherein, k is an integer;

[0135] (4) Grey system modeling and prediction;

[0136] The grey system model is:

[0137] ,

[0138] in, Indicates the value of the cumulative generated sequence, It represents the sequence of the average values ​​of the immediately adjacent sequences generated by accumulation. and are the least squares coefficients respectively, and N is the number of calculation factors for the two indicators of photovoltaic active power and load active power. In this case, N is 2. .

[0139] Using the least squares method The indicator calculation factor value y at time t is predicted and output.

[0140] (5) The results are reverse normalized;

[0141] The calculation factors of the two indicators, photovoltaic active power and load active power, are used to inversely normalize the predicted output of the gray system model to obtain the actual photovoltaic active power value. and load power value , load power value Included and , and They are i The active load power and reactive load power connected to the node.

[0142] Step 2: Distributed photovoltaic support control.

[0143] The photovoltaic active power adjustment range is , the photovoltaic reactive power adjustment range is, , PF is the power factor.

[0144] Step 3: Energy storage system regulation and control.

[0145] Energy storage system power The output adjustment range is: ,in is the maximum discharge power, The maximum charging power;

[0146] In order to ensure the continuity of energy storage output power, the capacity constraint of the SOC of the energy storage system is checked within the output power range. The formula is:

[0147] ,

[0148] ,

[0149] is the current SOC value of the energy storage system, For charging efficiency, is the discharge efficiency, is the capacity of the energy storage system, is the current power value of the energy storage system, For the time interval.

[0150] The coordinated control between stations is as follows:

[0151] After clarifying the self-regulation potential corresponding to the adjustable resources in the distribution network in units of substations, considering the coordination among multiple resources of source, load and storage and the cooperation among controllable reactive equipment, the inter-substation coordinated control of the distribution network in the region is converted into the upper / lower limit control that maximizes the dynamic load of the distribution network:

[0152] ,

[0153] in, for t The upper limit power carried by the distribution network feeder at any moment, for t The total power of load and energy storage in the distribution network at time h, R is the number of distribution network substations. The constraints include: substation transformer power transmission constraints, power flow constraints and warning power quality constraints.

[0154] Transformer power transmission constraints in the substation area:

[0155] ,

[0156] in, for t The distributed photovoltaic power generation power in the distribution network area h at the moment, , are the upper and lower limits of the transmission power of the transformer in the distribution network area h; optionally, the area corresponds to the node.

[0157] The power flow equation for power flow constraint is:

[0158] ,

[0159] in, is the set of end nodes of the distribution network branch, γ ( i ) is the set of first nodes of distribution network branches; , , are the branch resistance, reactance and current between node i and node j respectively; and are the active power and reactive power transmitted between node i and node j respectively; and are the node voltages of node i and node j respectively; , They are i The active output and reactive output of the distributed power sources connected to the node; and They are i The charging and discharging power of the energy storage to which the node is connected; , for i The node can interrupt the load active power and reactive power.

[0160] The warning power quality constraints limit the average voltage deviation of all substations in the distribution network to a preset limit range. Optionally, the preset limit is (-3%, +5%), (-5%, +7%), (-3%, +7%) or (-5%, +3%).

[0161] Through the differentiated normalization method, the load fluctuation and the response rate to power changes are smoothed, and the coordination and control level of the distribution network is improved.

[0162] Figure 3 A more specific schematic diagram of the hardware structure of a computer storage medium provided in this embodiment is shown, and the device may include: a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040 are connected to each other in communication within the device through the bus 1050.

[0163] The processor 1010 can be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of the present application.

[0164] The memory 1020 may be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 1020 may store an operating system and other application programs. When the technical solution provided in the embodiment of the present application is implemented by software or firmware, the relevant program code is stored in the memory 1020 and is called and executed by the processor 1010.

[0165] The input / output interface 1030 is used to connect the input / output module to realize information input and output. The input / output module can be configured in the device as a component (not shown in the figure), or it can be externally connected to the device to provide corresponding functions. The input device may include a keyboard, a mouse, a touch screen, a microphone, various sensors, etc., and the output device may include a display, a speaker, a vibrator, an indicator light, etc.

[0166] The communication interface 1040 is used to connect a communication module (not shown) to realize communication interaction between the device and other devices. The communication module can realize communication through a wired mode (such as USB, network cable, etc.) or a wireless mode (such as mobile network, WIFI, Bluetooth, etc.).

[0167] The bus 1050 includes a path that transmits information between the various components of the device (eg, the processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040).

[0168] It should be noted that, although the above device only shows the processor 1010, the memory 1020, the input / output interface 1030, the communication interface 1040 and the bus 1050, in the specific implementation process, the device may also include other components necessary for normal operation. In addition, it can be understood by those skilled in the art that the above device may also only include the components necessary for implementing the embodiment of the present application, and does not necessarily include all the components shown in the figure.

[0169] Based on the same inventive concept, corresponding to any of the above-mentioned embodiment methods, the present application also provides a non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the downlink communication method under high-speed movement as described in any of the above embodiments.

[0170] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, read-only compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device.

[0171] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0172] It should be noted that the serial numbers of the embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0173] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for controlling coordinated power support in a substation area, characterized in that: The method includes intra-station unit support control and inter-station coordinated control; The unit support control in the station area includes the following steps: Step 1: Distributed photovoltaic and load power forecast; (1) Determine the index calculation factors; the index calculation factors include: load prediction factor and photovoltaic prediction factor; (2) Data normalization; (3) Data preprocessing; (4) Grey system modeling and prediction; (5) Denormalization of prediction results; Step 2: Distributed photovoltaic support control; Step 3: Energy storage system regulation and control; The inter-station coordinated control includes the following steps: coordination among multiple resources such as source, load and storage, and the inter-station coordinated control of the distribution network is converted into the control that maximizes the upper or lower limit of the dynamic load of the distribution network; In step 1, the load prediction factors include load active power factor and load reactive power factor: extract the historical load data at point F every day, where F is an integer. The load active power factor includes: the load active power of the week, time and one hour before the current moment; the load reactive power factor includes: the load reactive power of the week, time and one hour before the current moment; Photovoltaic prediction factors, including photovoltaic power factor: extract the historical photovoltaic power data at daily F point. The photovoltaic power factor includes: time, photovoltaic capacity, photovoltaic active power, photovoltaic reactive power and photovoltaic power data one hour before the current time; The data normalization process includes: normalizing the index calculation factor; the normalization process uses one or more of the positive index, interval index or reverse index; Normalization formula for positive indicators: In the formula, , They are the maximum and minimum values ​​of the index calculation factors in several low-voltage distribution substations. is the actual value of the indicator calculation factor, is the normalized value of the indicator calculation factor, i is the number of indicator calculation factors and is an integer; The load active power adopts the interval index normalization processing formula: In the formula, is the middle value of the interval for the indicator calculation factor, =( + ) / 2, max means taking the maximum value; The photovoltaic active power adopts the reverse index normalization processing formula: ； The data preprocessing includes: The original data normalized by the indicator calculation factor Accumulate and process to get accumulated data ,in Respectively represent the normalized values ​​of the indicator calculation factors 0,1 ,F-1 extraction point data, Wherein, k is an integer; The grey system modeling prediction includes: the grey system model is: , in, It means to accumulate the values ​​of the generated sequence. It represents the sequence of the average values ​​of the immediately adjacent sequences generated by accumulation. and are the least squares coefficients respectively, N is the number of index calculation factors, =0.5[ + ]; Using the least squares method y = t+ Predict and output the indicator calculation factor value y at time t; The prediction result inverse normalization includes: The index calculation factors are taken as photovoltaic active power and load active power, and the predicted output solved by the grey system model is inversely normalized to obtain the actual photovoltaic active power value. and load power value , load power value Included and , and They are i Active load power and reactive load power connected to the node; The distributed photovoltaic support control is as follows: the photovoltaic active power adjustment interval is [0~ ], the photovoltaic reactive power adjustment range is , PF is the power factor; The energy storage system regulation control is: energy storage system power The output adjustment range is: ,in is the maximum discharge power, The maximum charging power; In order to ensure the continuity of energy storage output power, the capacity constraint verification formula for the SOC of the energy storage system within the output power range is: ， ， is the current SOC value of the energy storage system, For charging efficiency, is the discharge efficiency, is the capacity of the energy storage system, is the current power value of the energy storage system, is the time interval; The conversion of the inter-station coordinated control of the distribution network into a control that maximizes the upper or lower limit of the dynamic load of the distribution network includes: in, for t The upper limit power carried by the distribution network feeder at any moment, for t The total power of load and energy storage in the distribution network at time h, R is the number of distribution network areas; Constraints include: power transmission constraints of transformers in the substation area, power flow constraints, and alert power quality constraints; Transformer power transmission constraints in the substation area: in, for t The distributed photovoltaic power generation power in the distribution network area h at the moment, and is the upper and lower limits of the transmission power of the transformer in the distribution network area h; the area corresponds to the node; The power flow equation for power flow constraint is: in, is the set of end nodes of the distribution network branch, γ ( i ) is the set of first nodes of distribution network branches; , , are the branch resistance, reactance and current between node i and node j respectively; and are the active power and reactive power transmitted between node i and node j respectively; and are the node voltages of node i and node j respectively; , They are i The active output and reactive output of the distributed power sources connected to the node; and They are i The charging and discharging power of the energy storage to which the node is connected; , for i The node can interrupt the load active power and reactive power; The warning power quality constraints limit the average voltage deviation of all distribution network sections to within the preset limit range.

2. A coordinated power support control system for a substation area, wherein the coordinated power support control system for a substation area executes the method of claim 1 when in operation, characterized in that: The system includes distributed photovoltaics, energy storage systems, loads and substations, which are connected through a distribution network; the distribution network includes power equipment and feeder lines; there are multiple distributed photovoltaics as power sources, and there are multiple substations distributed in the distribution network, multiple power loads are distributed in the distribution network and each substation, one or more energy storage systems are arranged at one or more nodes of the distribution network, and distributed photovoltaics are connected to the power grid through different substations as power sources.

3. A computer storage medium, comprising a memory, a processor, and a computer program stored in the memory and executed by the processor, characterized in that: When the processor executes the computer program, the method according to claim 1 is implemented.

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