Method, device and equipment for calculating line loss in distribution network section with distributed power access

Abstract

The present invention proposes a method, device and equipment for calculating line loss in a distribution network interval with distributed power access, comprising: collecting distribution network system data; establishing an objective function based on the distribution network system data to obtain an interval value of line loss of the distribution network system within a time period, wherein the constraints of the objective function include flow constraints and node power limit constraints; the node power limit constraints include load node power constraints, PV node voltage constraints and PV node reactive power constraints; the load node power constraints include interval constraints and power constraints, and the PV node refers to a node with a given active power P and voltage amplitude V; splitting the interval constraints by a bisection method, and replacing the equation containing the integral of the power constraint with the power constraint sum equation according to the segmentation result of the interval constraint; obtaining a linear programming of the line loss fluctuation interval based on the above constraints and the objective function, and solving the linear programming to obtain the distribution network interval line loss.

Description

Technical Field

[0001] The present invention belongs to the technical field of power flow analysis, and in particular relates to a method, device and equipment for calculating line loss in a distribution network section to which a distributed power source is connected. Background Art

[0002] The primary method for studying power grid line loss is to use the power and voltage at each user-side node to derive an expression for line loss at any given moment, then integrate it to calculate the total line loss for a specific time period. However, distribution network lines are complex, and users can only collect information such as total power, maximum current, minimum current, and average current for a specific time period. Sometimes user-side data is even missing, making it difficult to accurately determine line loss. Methods such as the equivalent resistance method and the average current method are often used to approximate distribution network loss, but these methods only provide an approximate line loss and cannot accurately determine the fluctuation range of line loss. Summary of the Invention

[0003] In response to the above problems, the present invention proposes a method for calculating line loss in a distribution network section where a distributed power source is connected, comprising:

[0004] Collect distribution network system data;

[0005] An objective function is established based on the distribution network system data to obtain an interval value of the line loss of the distribution network system within a time period. The constraints of the objective function include power flow constraints and node power limit constraints. The node power limit constraints include load node power constraints, PV node voltage constraints, and PV node reactive power constraints. The load node power constraints include interval constraints and power constraints. A PV node refers to a node with a given active power P and voltage amplitude V.

[0006] The interval constraint is divided by a bisection method, and the equation containing the integral of the power constraint is replaced by the power constraint summation equation according to the result of the interval constraint division;

[0007] According to the above constraints and objective function, a linear programming of the line loss fluctuation range is obtained, and the linear programming is solved to obtain the line loss of the distribution network interval.

[0008] Furthermore, the objective function is:

[0009]

[0010] Among them, e is the real part of the node voltage, f is the imaginary part of the node voltage, e i and e j is the real part of the voltage at nodes i and j, f i and f j is the imaginary part of the voltage at nodes i and j; R ij represents the resistance of the branch connecting node i and node j, X ijRepresents the reactance of the branch connecting node i and node j.

[0011] Furthermore, the power flow constraint f(P,e,f)=0 includes:

[0012]

[0013]

[0014]

[0015] Among them, PQ node refers to the node with given active power P and reactive power Q; SB node refers to the node with given voltage amplitude and phase angle; G ij B represents the real part of the admittance of the branch connecting node i and node j, ij is the imaginary part of the branch admittance connecting node i and node j; P Li is the active power of load node i, Q Li is the reactive power of load node i; V Gi is the voltage amplitude of the generator node i, P Gi is the active power of generator node i;

[0016] The node power limit constraint g(P,e,f)≤0 includes:

[0017] Load node power constraints:

[0018] PV node voltage constraints:

[0019] PV node reactive power constraint:

[0020] in, is the minimum power of load node i, is the maximum power of load node i, is the minimum voltage of node i, is the maximum voltage of node i; is the minimum reactive power of node i, is the maximum reactive power of node i.

[0021] Furthermore, the linear programming is:

[0022] min / max F(P,e,f)

[0023] st

[0024]

[0025] Where F(P,e,f) is the objective function, f(P,e,f)=0 is the power flow constraint, g(P,e,f)≤0 is the node power limit constraint, e is the real part of the node voltage, and f is the imaginary part of the node voltage.

[0026] Furthermore, the load node power constraints include:

[0027]

[0028] in, is an interval constraint; is the power constraint, which is an equation containing integrals; is the minimum power of load node i, is the maximum power of load node i, P Li is the power of load node i, is the reading of the watt-hour meter at load node i at time q, is the reading of the electricity meter of load node i at time q-1.

[0029] Furthermore, the interval constraint is divided by a bisection method, and the equation containing the integral of the power constraint is replaced by the power consumption constraint summation equation according to the result of the interval constraint division, including:

[0030] Use the binary method to split the interval constraint and divide the interval value P Li Dichotomized into P Li1 and P Li2 , the corresponding time intervals are t i1 , t i2 ;

[0031] According to m load nodes, 2m time intervals are determined and divided into 2 m subintervals, as the segmentation results of the interval constraints;

[0032] An approximate method is used to replace the equation containing the integral of the power constraint with the power constraint summation equation;

[0033] The power constraint summation equation is:

[0034]

[0035] Among them, t i1 t i1 The intersection of different combinations of other 2m-2 time intervals, t i2 t i2 The intersection of different combinations of other 2m-2 time intervals; for The average value of for The average value of for The average value of .

[0036] Furthermore, the maximum power of load node i and minimum value Calculate it as follows:

[0037]

[0038] in, is the voltage, For current.

[0039] On the other hand, the present invention provides a device for calculating line loss in a distribution network section connected to a distributed power source, characterized in that the device comprises:

[0040] Data acquisition module, used to collect data from distribution network system;

[0041] An objective function establishment module is used to establish an objective function based on the distribution network system data to obtain an interval value of the line loss of the distribution network system within a time period. The constraints of the objective function include power flow constraints and node power limit constraints. The node power limit constraints include load node power constraints, PV node voltage constraints, and PV node reactive power constraints. The load node power constraints include interval constraints and power constraints. The PV node refers to a node with a given active power P and voltage amplitude V.

[0042] An interval segmentation module is used to segment the interval constraint using a binary method, and replace the equation containing the integral of the power constraint with the power consumption constraint summation equation according to the segmentation result of the interval constraint;

[0043] The line loss interval solving module obtains the linear programming of the line loss fluctuation interval according to the above constraints and the objective function, and solves the linear programming to obtain the distribution network interval line loss.

[0044] On the other hand, the present invention proposes an electronic device, including a memory, a processor, and a computer program stored in the memory and runnable on the processor, characterized in that when the processor executes the program, it implements a method for calculating line loss in a distribution network section with distributed power access as described above.

[0045] On the other hand, the present invention proposes a non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, it implements the above-mentioned method for calculating line loss in a distribution network section with distributed power supply access.

[0046] Beneficial effects of the present invention: The method of the present invention improves on the traditional method of line loss calculation, reduces the error caused by average power, and improves the accuracy of line loss calculation; the present invention is applicable to the situation where user-side collected data is missing, for example, under the premise that user-side power data is not collected, the present invention can still calculate the line loss of the time period to be calculated; at the same time, the present invention is applicable to the distribution network with distributed power supply access, which helps to promote the improvement of line loss management level in the era of vigorous development of new energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are embodiments of the present invention.

[0048] Figure 1 A flow chart of a method for calculating line loss in a distribution network interval based on an interval optimization algorithm provided by an embodiment of the present invention;

[0049] Figure 2 It is a 4-node distribution network system in an embodiment of the present invention;

[0050] Figure 3 It is a schematic diagram of using the dichotomy method to perform constraint condition segmentation in the present invention. DETAILED DESCRIPTION

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0052] Figure 1 A flow chart of a method for calculating line loss in a distribution network interval based on an interval optimization algorithm of the present application is shown. As shown in the figure, the method specifically includes the following steps:

[0053] Step A: Collect distribution network system data;

[0054] The collected data includes the user-side ID of the distribution network system, the voltage at the end of the transmission network at a certain moment, the active and reactive energy, voltage, and current of the distributed generation node at that moment on the day to be requested, and the active and reactive energy, voltage, and current data of the load node at the hour of the day to be requested. The specific methods for data collection are conventional in the field and will not be detailed here.

[0055] Assume that the user side nodes of a distribution network system are numbered 1 to n, and the voltage at the end of the transmission network at time q is collected in the measurement system. The active and reactive energy of the distributed power generation node at the hour q on the day to be determined Voltage Current Active and reactive energy values ​​of the load node at the hour of the day to be determined Voltage Current

[0056] by Figure 2 Taking the 4-node system shown as an example, node 1 is the end of the transmission network, node 2 is the first section of the distribution network, node 3 is the load, and node 4 is the access to the distributed power supply. N is the voltage at the end of the transmission network, and the voltage at time q can be read by a voltmeter P L is the active power of the load node, and the data is read every hour (once an hour, 24 times in total); G is the active output of the distributed power supply, and the data is read every hour (once an hour, a total of 24 times). For the sake of simplicity, assume that the reactive load and the reactive output of the distributed power supply are both 0. Note that U N , P L , P G are functions of time t.

[0057] Step B: Establish an objective function based on the distribution network system data to obtain the interval value of the line loss of the distribution network system within a time period. The constraints of the objective function include power flow constraints and node power limit constraints; node power limit constraints include load node power constraints, PV node voltage constraints, and PV node reactive power constraints; load node power constraints include interval constraints and power constraints; PV nodes refer to nodes with given active power P and voltage amplitude V.

[0058] The line loss of the distribution network in a certain period is generally expressed as To express, where F(U N ,P L ,P G is the line loss power of the section at a specified time, when U N 、P L 、P G When it is determined, the network loss of the entire distribution network at this specified time section can be accurately solved by power flow calculation. However, based on the relevant data in step A and the fact that the formula is an integral expression, it is impossible to solve, that is, it is impossible to obtain the line loss value of the distribution network system within a period of time (for example, from time q-1 to time q). However, if the integral is converted into a sum, the solution can be completed. Therefore, the present invention obtains an interval value of line loss through an optimization method, and the actual line loss is within this interval. The objective function is as follows;

[0059]

[0060] Among them, e is the real part of the node voltage, f is the imaginary part of the node voltage, e i and e j is the real part of the voltage at nodes i and j, f i and f j is the imaginary part of the voltage at nodes i and j; R ij represents the resistance of the branch connecting node i and node j, X ij Represents the reactance of the branch connecting node i and node j.

[0061] The constraints of the objective function include:

[0062] Power flow constraint f(P,e,f)=0

[0063] The power flow constraint f(P,e,f)=0 includes:

[0064]

[0065]

[0066]

[0067] Among them, PQ node refers to the node with given active power P and reactive power Q; SB node refers to the node with given voltage amplitude and phase angle; G ij B represents the real part of the admittance of the branch connecting node i and node j, ij is the imaginary part of the branch admittance connecting node i and node j; P Li is the active power of load node i, Q Li is the reactive power of load node i; V Gi is the voltage amplitude of the generator node i, P Gi is the active power of generator node i;

[0068] The node power limit constraint g(P,e,f)≤0 includes:

[0069] Load node power constraints:

[0070] PV node voltage constraints:

[0071] PV node reactive power constraint:

[0072] in, is the minimum power of load node i, is the maximum power of load node i, is the minimum voltage of node i, is the maximum voltage of node i; is the minimum reactive power of node i, is the maximum reactive power of node i.

[0073] For the objective function F(P,e,f) above, which is the sum of line losses on all lines, we can use another expression:

[0074]

[0075] Among them, R ij represents the resistance of the branch connecting node i and node j, X ij Represents the branch reactance connecting node i and node j. Li is the active power of load node i, is the minimum power of load node i, is the maximum power of load node i; is the minimum voltage of node i, is the maximum voltage of node i; is the minimum reactive power of node i, is the maximum reactive power of node i.

[0076] Then the above objective function can form a planning

[0077]

[0078] However, this planning is still a nonlinear planning and cannot be solved directly using existing tools. The main problem is the load node power P L It is impossible to obtain the data of each point in real time. Only the maximum and minimum values ​​are known. The load node power constraint cannot be obtained. Therefore, it is necessary to process the load node power constraint so that the non-programming of the above formula (9) is transformed into a linear programming. The linear programming solver can be called in MATLAB using the YALMIP toolbox. Therefore, the present invention mainly uses the bisection method to solve the load node power constraint by interval partitioning.

[0079] by Figure 2 Taking the 4-node system shown in the figure as an example, the load node power constraints and the distributed generation active power output constraints are:

[0080]

[0081] In order to fully explain the dichotomy, in this example, G However, in practice, the data collection equipment on the distributed power supply side is often high-density and can collect real-time active output, so the main consideration is to use binary processing on the load node power.

[0082] In the above formula (10), t is the time variable, and is the reading of the watt-hour meter of load node 3 at time q and q-1, and is the reading of the distributed power meter of node 4 at time q and q-1, is the average voltage of the voltmeter at the end of the transmission network. is the maximum and minimum value of the load power, It is the maximum and minimum value of the active power output of the distributed power source.

[0083] In formula (10), the first and second constraints are interval constraints, and the third and fourth constraints are power constraints. When solving the constraints of formula (10), the voltage constraint at the end of the transmission network is also involved. Since the voltage variation at the end of the transmission network is small, Therefore, this constraint can be ignored.

[0084] The maximum and minimum values ​​of the power range in formula (10) are obtained as follows:

[0085] (1) Maximum and minimum active output of distributed power generation nodes

[0086] At the distributed power source connected to the distribution network, there are voltage meters, current meters and watt-hour meters to record data. The data are read at 24 o'clock every day, including: voltage Current Maximum active output of distributed power generation and minimum value It can be obtained by the following formula:

[0087]

[0088] Where, are the maximum and minimum rated active output of distributed generation respectively.

[0089] (2) Maximum and minimum load node power

[0090] At the distribution transformer or low-voltage user side connected to the distribution network, there are voltage meters, current meters and watt-hour meters to record data. The data are read at the top of the hour (24:00) every day, including: voltage Current Maximum active load and minimum value It can be obtained by the following formula:

[0091]

[0092] It can be seen from the above formula (10) that the integral of the product of load node power and time is equal to the power. The interval constraints (the first and second constraints) in the constraints of formula (10) are divided by bisection, and the power constraints (the third and fourth constraints) in the constraints of formula (10) are replaced by summation equations using an approximate method.

[0093] First, the interval number P L and P G Divide them into two parts, namely P L1 、P L2 and P G1 、P G2 , let the time within the corresponding power range be t 11 , t 12 and t 21 , t 22 Among them, P L Indicates the number of intervals [P L mi n,P L max ], P G Indicates the number of intervals [P G min ,P G max ].

[0094] like Figure 3 As shown, t 11 correspond and Crossover time, t 12 correspond and Crossover time, t 21 correspond and Crossover time, t 22 correspond and Crossover time. for The average value of for The average value of .

[0095] Then, based on the above interval division, the summation equation is used to approximately replace the power constraints (the third and fourth constraints) in the constraints of formula (10)

[0096]

[0097]

[0098] in, for The average value of for The average value of for The average value of for The average value of .

[0099] Therefore, the fluctuation range of line loss of the 4-node distribution network system can be solved by the following linear programming:

[0100]

[0101] Where, F (x,y), Indicates the lower and upper limits of the line loss power of a section at a certain moment when x and y are interval numbers.

[0102] In the case of multiple load nodes, the interval value P Li Dichotomized into P Li1 、P Li2 , the corresponding time intervals are t i1 , t i2 ; Assuming there are m load nodes, there are 2m time intervals in total, with a total of 2 m Combination method, that is, divide into 2 m The power constraint formula can be rewritten as follows:

[0103]

[0104] Among them, t i1 t i1 The intersection of different combinations of other 2m-2 time intervals, t i2 t i2 The intersection of different combinations of other 2m-2 time intervals. for The average value of for The average value of for The average value of .

[0105] An embodiment of the present invention further provides a line loss calculation device for a distribution network section connected to a distributed power source, which is used to implement the above line loss calculation method, including:

[0106] Data acquisition module, used to collect data from distribution network system;

[0107] An objective function establishment module is used to establish an objective function based on the distribution network system data to obtain an interval value of the line loss of the distribution network system within a time period. The constraints of the objective function include power flow constraints and node power limit constraints. The node power limit constraints include load node power constraints, PV node voltage constraints, and PV node reactive power constraints. The load node power constraints include interval constraints and power constraints. The PV node refers to a node with a given active power P and voltage amplitude V.

[0108] An interval segmentation module is used to segment the interval constraint using a binary method, and replace the equation containing the integral of the power constraint with the power consumption constraint summation equation according to the segmentation result of the interval constraint;

[0109] The line loss interval solving module obtains the linear programming of the line loss fluctuation interval according to the above constraints and the objective function, and solves the linear programming to obtain the distribution network interval line loss.

[0110] In one embodiment, the objective function is:

[0111]

[0112] Among them, e is the real part of the node voltage, f is the imaginary part of the node voltage, e i and e j is the real part of the voltage at nodes i and j, f i and f j is the imaginary part of the voltage at nodes i and j; R ij represents the resistance of the branch connecting node i and node j, X ij Represents the reactance of the branch connecting node i and node j.

[0113] In one embodiment, the power flow constraint f(P,e,f)=0 includes:

[0114]

[0115]

[0116]

[0117] Among them, PQ node refers to the node with given active power P and reactive power Q; SB node refers to the node with given voltage amplitude and phase angle; G ij B represents the real part of the admittance of the branch connecting node i and node j, ij is the imaginary part of the branch admittance connecting node i and node j; P Li is the active power of load node i, Q Li is the reactive power of load node i; V Gi is the voltage amplitude of the generator node i, P Giis the active power of generator node i;

[0118] The node power limit constraint g(P,e,f)≤0 includes:

[0119] Load node power constraints:

[0120] PV node voltage constraints:

[0121] PV node reactive power constraint:

[0122] in, is the minimum power of load node i, is the maximum power of load node i, is the minimum voltage of node i, is the maximum voltage of node i; is the minimum reactive power of node i, is the maximum reactive power of node i.

[0123] In one embodiment, the linear programming is:

[0124] min / max F(P,e,f)

[0125] st

[0126]

[0127] Where F(P,e,f) is the objective function, f(P,e,f)=0 is the power flow constraint, g(P,e,f)≤0 is the node power limit constraint, e is the real part of the node voltage, and f is the imaginary part of the node voltage.

[0128] In one embodiment, the load node power constraint includes:

[0129]

[0130] in, is an interval constraint; is the power constraint, which is an equation containing integrals; is the minimum power of load node i, is the maximum power of load node i, P Li is the power of load node i, is the reading of the watt-hour meter at load node i at time q, is the reading of the electricity meter of load node i at time q-1.

[0131] In one embodiment, the interval constraint is divided by a binary method, and the equation containing the integral of the power constraint is replaced by the power consumption constraint summation equation according to the result of the interval constraint division, including:

[0132] Use the binary method to split the interval constraint and divide the interval value P Li Dichotomized into P Li1 and P Li2 , the corresponding time intervals are t i1 , t i2 ;

[0133] According to m load nodes, 2m time intervals are determined and divided into 2 m subintervals, as the segmentation results of the interval constraints;

[0134] An approximate method is used to replace the equation containing the integral of the power constraint with the power constraint summation equation;

[0135] The power constraint summation equation is:

[0136]

[0137] Among them, t i1 t i1 The intersection of different combinations of other 2m-2 time intervals, t i2 t i2 The intersection of different combinations of other 2m-2 time intervals; for The average value of for The average value of for The average value of .

[0138] In one embodiment, the maximum power of load node i and minimum value Calculate it as follows:

[0139]

[0140] in, is the voltage, For current.

[0141] An embodiment of the present invention further provides an electronic device comprising the following components: a processor, a communications interface, a memory, and a communications bus. The processor, the communications interface, and the memory communicate with each other via the communications bus. The processor can invoke logic instructions in the memory to execute the method for calculating line loss between distribution network sections for distributed power generation access described in the above embodiment of the present invention.

[0142] In addition, the logical instructions in the above-mentioned memory can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0143] An embodiment of the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, it is implemented to execute a method for calculating line loss in a distribution network section with distributed power access in the above embodiment.

[0144] This embodiment is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for calculating line loss in a distribution network section where a distributed power source is connected, comprising: Collect distribution network system data; An objective function is established based on the distribution network system data to obtain the interval value of the line loss of the distribution network system within a period of time. The constraints of the objective function include power flow constraints and node power limit constraints. The node power limit constraints include load node power constraints, PV node voltage constraints, and PV node reactive power constraints. The load node power constraints include interval constraints and power constraints. The PV node refers to a node with a given active power P and voltage amplitude V. The objective function is: ， in, e is the real part of the node voltage, f is the imaginary part of the node voltage, e i and e j For nodes i and j The real part of the voltage, f i and f j For nodes i and j The imaginary part of the voltage; R ij Indicates connection i Node and j The resistance of the branch at the node, X ij Indicates connection i Node and j The branch reactance of the node; The power flow constraint include: ， Among them, PQ node refers to the node with given active power P and reactive power Q; SB node refers to the node with given voltage amplitude and phase angle; G ij To indicate connection i Node and j The real part of the branch admittance of the node, B ij To indicate connection i Node and j The imaginary part of the branch admittance of the node; Load node i The active power, Load node i Reactive power; For generator nodes i The voltage amplitude, For generator nodes i Active power; The node power limit constraint include: Load node power constraints: , PV node voltage constraints: , PV node reactive power constraint: , in, Load node i The minimum power, Load node i The maximum power, For nodes i Minimum voltage, For nodes i Maximum voltage; For nodes i Minimum reactive power, For nodes i Maximum reactive power; The load node power constraints include: ， in, is an interval constraint; is the power constraint, which is an equation containing integrals; Load node i The minimum power, Load node i The maximum power, Load node i power, Load node i The electricity meter at time q The degree, Load node i The electricity meter at time q -1 degree; The interval constraint is divided by a bisection method, and the equation containing the integral of the power constraint is replaced by the power constraint summation equation according to the result of the interval constraint division; According to the above constraints and objective function, a linear programming of the line loss fluctuation range is obtained, and the linear programming is solved to obtain the line loss of the distribution network interval.

2. The method for calculating line loss in a distribution network section where a distributed power source is connected according to claim 1, characterized in that: The linear programming is: ， in, is the objective function, For trend constraints, is the node power limit constraint; e is the real part of the node voltage, f is the imaginary part of the node voltage.

3. The method for calculating line loss in a distribution network section where a distributed power source is connected according to claim 1, characterized in that: The interval constraint is divided by a binary method, and the equation containing the integral of the power constraint is replaced by the power consumption constraint summation equation according to the result of the interval constraint division, including: Use the binary method to split the interval constraint and divide the interval value Dichotomized and , and the corresponding time intervals are ; According to m load nodes, 2m time intervals are determined and divided into subintervals, as the segmentation results of the interval constraints; An approximate method is used to replace the equation containing the integral of the power constraint with the power constraint summation equation; The power constraint summation equation is: ， in, for The intersection of different combinations of other 2m-2 time intervals, for The intersection of different combinations of other 2m-2 time intervals; for The average value of for The average value of for The average value of .

4. The method for calculating line loss in a distribution network section where a distributed power source is connected according to claim 1, wherein: The load node Maximum power and minimum value Calculate it as follows: ， in, is the voltage, For current.

5. A line loss calculation device for a distribution network section with access to a distributed power source, characterized in that: The device comprises: Data acquisition module, used to collect distribution network system data; The objective function establishment module is used to establish an objective function based on the distribution network system data to obtain the interval value of the line loss of the distribution network system within a time period. The constraints of the objective function include power flow constraints and node power limit constraints. The node power limit constraints include load node power constraints, PV node voltage constraints, and PV node reactive power constraints. The load node power constraints include interval constraints and power constraints. The PV node refers to the node with a given active power P and voltage amplitude V. The objective function is: ， in, e is the real part of the node voltage, f is the imaginary part of the node voltage, and For nodes and j The real part of the voltage, and For nodes and j The imaginary part of the voltage; Indicates connection Node and j The resistance of the branch at the node, Indicates connection Node and j The branch reactance of the node; The power flow constraint include: ， Among them, PQ node refers to the node with given active power P and reactive power Q; SB node refers to the node with given voltage amplitude and phase angle; To indicate connection Node and j The real part of the branch admittance of the node, To indicate connection Node and j The imaginary part of the branch admittance of the node; Load node The active power, Load node Reactive power; For generator nodes The voltage amplitude, For generator nodes Active power; The node power limit constraint include: Load node power constraints: , PV node voltage constraints: , PV node reactive power constraint: , in, Load node The minimum power, Load node The maximum power, For nodes Minimum voltage, For nodes Maximum voltage; For nodes Minimum reactive power, For nodes Maximum reactive power; The load node power constraints include: ， in, is an interval constraint; is the power constraint, which is an equation containing integrals; Load node The minimum power, Load node The maximum power, Load node power, Load node The electricity meter at time q The degree, Load node The electricity meter at time q -1 degree; An interval segmentation module is used to segment the interval constraint using a binary method, and replace the equation containing the integral of the power constraint with the power consumption constraint summation equation according to the segmentation result of the interval constraint; The line loss interval solving module is used to obtain the linear programming of the line loss fluctuation interval according to the above constraints and the objective function, and solve the linear programming to obtain the distribution network interval line loss.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, it implements the method for calculating line loss in a distribution network section with distributed power access as described in any one of claims 1 to 3.

7. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, it implements a method for calculating line loss in a distribution network section with access to a distributed power source as described in any one of claims 1 to 3.

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