CN113659574B - Power distribution network closed-loop simulation platform with phase angle difference and simulation method - Google Patents

Abstract

The invention relates to a combined-loop simulation platform and a combined-loop simulation method for a power distribution network with phase angle difference, wherein the combined-loop simulation platform comprises a drawing function module and a loop calculation module, the drawing function module comprises a drawing interface and an electric equipment model adding module, starting power supply points at the middle and low voltage sides of each 220kV transformer model, adding the corresponding electric equipment model to the drawing interface through the electric equipment model adding module according to the actual grid structure of a regional power grid, setting parameters and states of each electric equipment model and connecting the electric equipment models with each other according to the actual grid structure of the regional power grid, and finally drawing a power flow simulation graph taking the middle and low voltage sides of each 220kV transformer model as the starting power supply points. The method can effectively solve the problems that the existing phase angle difference distribution network joint-solving loop is manually calculated and analyzed by technicians, the conclusion error is large, the analysis result is simple and has little significance for actual operation, and the operation is carried out according to the analysis result, so that the power grid accident and risk are easy to occur.

Description

Power distribution network closed-loop simulation platform with phase angle difference and simulation method

Technical Field

The utility model relates to a distribution network field especially relates to a take phase angle difference distribution network to close and break up ring simulation platform and simulation method.

Background

The regional power grid is not provided with a simulation platform special for simulating the closed-loop of the power distribution network with the phase angle difference, the closed-loop of the power distribution network with the phase angle difference is manually calculated and analyzed by technicians, the conclusion error is large, the analysis result is simple, the practical operation significance is not great, the operation is carried out according to the analysis result, and the power grid accident and risk are easy to occur.

Disclosure of Invention

The invention aims to provide a loop closing and opening simulation platform for a power distribution network with phase angle difference, which can effectively solve the problems that the existing loop closing and opening simulation platform for the power distribution network with phase angle difference is easy to operate according to the analysis result and easy to cause power grid accidents and risks due to large conclusion error and simple analysis result and little significance to actual operation through manual calculation and analysis of technicians.

The technical scheme adopted for solving the technical problems is as follows: the power distribution network combined-loop simulation platform with the phase angle difference comprises a drawing function module and a loop calculation module, wherein the drawing function module comprises a drawing interface and an electric equipment model adding module, starting power supply points at the middle and low voltage sides of each 220kV transformer model, adding the corresponding electric equipment model to the drawing interface through the electric equipment model adding module according to the actual grid structure of a regional power grid, setting parameters and states of each electric equipment model and connecting the parameters and states with each other according to the actual grid structure of the regional power grid, and finally drawing a power flow simulation diagram taking the middle and low voltage sides of each 220kV transformer model as the starting power supply points; the tide simulation diagram comprises all 110kV line models connected with medium voltage measurement of a 220kV transformer model and all 35kV line models connected with the low voltage side of the 220kV transformer model; 110kV transformer models connected with all 110kV line models, 10kV line models and 35kV line models connected with each 110kV transformer model; a 35 transformer model connected to each 35kV line model, and a 10kV line model connected to the 35kV transformer model; and all 110kV line models, 35kV line models and switch models on 10kV line models.

Furthermore, a power supply system of 110kV or below adopts an open-loop operation mode of a power grid loop model structure, when maintenance is needed, the open-loop operation mode is closed-loop operated through a switch model of a closed-loop point, and at the moment, a loop model is formed; by closing the switch model of each open loop point in each 220kV partition tidal current graph, each different loop model can be formed; the loop calculation module can calculate the corresponding loop model current of each loop model; the method comprises a 35kV loop model with phase angle difference and other loop models without phase angle difference;

when the circulation calculation module calculates, the circulation calculation module mainly comprises: in each loop model, comparing the current value and the current phase of each electrical equipment model with the protection fixed value of the electrical equipment model, and generating an analysis report; in the analysis report, whether the protection fixed value of each electric equipment model needs to be adjusted or not is pointed out; when the protection fixed value of the electrical equipment model is larger than the current value, adjustment is not needed; when the protection fixed value of the electrical equipment model is smaller than or equal to the current value, the protection fixed value is required to be increased;

when the circulation calculation module calculates, the method further comprises the following steps: according to the resistance and inductance of the loop model to the electrical equipment model, calculating an impact current value when the open loop point is closed, comparing the impact current value with the rated current value of each electrical equipment model, judging whether the safe operation of the equipment is affected, and displaying the result in an analysis report.

Further, the analysis report also comprises a corresponding power flow simulation diagram, and the analysis report shows that the corresponding power flow simulation diagram is consistent with the loop model calculated by the loop calculation module.

The intelligent simulation method for the phase angle difference solution loop of the power distribution network is characterized by comprising the following steps of: the method comprises the following steps:

according to an actual grid structure of a regional power grid, using 220kV transformers as units, adding corresponding electric equipment models to a drawing interface one by one through an electric equipment model adding module on the drawing interface of a simulation platform, completing interconnection and parameter setting of the electric equipment models according to the actual grid structure, and finally drawing a tide simulation diagram taking the middle and low voltage sides of each 220kV transformer model as initial power supply points; the tide simulation diagram comprises all 110kV line models connected with medium voltage measurement of a 220kV transformer model and all 35kV line models connected with the low voltage side of the 220kV transformer model; 110kV transformer models connected with all 110kV line models, 10kV line models and 35kV line models connected with each 110kV transformer model; a 35 transformer model connected to each 35kV line model, and a 10kV line model connected to the 35kV transformer model; and all the 110kV line models, 35kV line models and switch models on the 10kV line models; each 220kV transformer in the actual grid structure of the regional power grid corresponds to one tide simulation diagram, and each tide simulation diagram is named and stored independently; the input of parameters comprises resistance and inductance;

step (2), according to the real-time value of the actual grid structure of the regional power grid, recording the voltage value and the load value of each electrical equipment model in the tide simulation diagram in real time;

step (3), defining all types of switch models in each tide simulation graph according to an actual grid structure of the regional power grid, wherein the switch model types comprise four types of a loop-opening switch model, a loop-closing switch model, a standby loop-opening switch model and a common switch model; setting the states of each switch model, wherein the switch model states comprise an operation state, a hot standby state and a cold standby state;

setting current protection fixed values of all the switch models in each tide simulation graph, respectively setting three sections of current protection fixed values of each switch model, and setting names, fixed value values, protection action time and tide direction of each section of current protection fixed values;

step (5), carrying out uninterrupted load power supply transfer simulation operation according to the condition of maintenance arrangement; firstly, a corresponding tide simulation diagram is found out, and simulation operation is carried out in the corresponding tide simulation diagram;

if the to-be-overhauled line model is a 35kV line model, firstly, respectively adjusting the types of two switch models at two sides of the to-be-overhauled line model into a loop-opening switch model and a standby loop-opening switch model;

step (6), modifying the state of a closed-loop switch model of an open-loop point on a circuit model of the same voltage class directly connected with the circuit model to be overhauled into a closed state to form a loop model;

step (7), obtaining a loop model current value of the loop model in the step (6) through a loop calculation function of the system, comparing the loop model current value with the current carrying capacity of a transformer model and a wire model in a tide simulation diagram, and if the current carrying capacity exceeds the current carrying capacity, performing current reduction simulation;

step (8), during current reduction simulation, firstly performing current reduction simulation of the same voltage level, screening out all 35kV line models which have topological connection relation with the loop model, and defining the 35kV line models as to-be-transferred 35kV line models; according to the principle of distance, judging whether the corresponding 35kV line model is suitable for current reduction simulation of the same voltage level in sequence; when judging, firstly, adjusting the state of a loop closing switch model on an open loop point on a to-be-transferred 35kV line model led out by another 110kV transformer model to be closed, then adjusting the state of a switch model on the 35kV line model led out by the 110kV transformer model on the original loop model to be open to form a new loop model, and then carrying out loop calculation;

when the current value of the obtained loop model does not exceed the temperature rise current value, finishing the current reduction simulation of the same voltage class, and positioning and closing a new loop model formed by the to-be-transferred 35kV line model and the corresponding 110kV transformer model;

if the obtained loop model current value exceeds the temperature rise current value, judging that the 35kV power supply circuit is not suitable for the current reduction simulation of the same voltage level, and judging the 35kV power supply circuit at the next distance until the 35kV power supply circuit suitable for the current reduction simulation of the same voltage level is encountered; if all 35kV power supply circuits are not suitable for the current reduction simulation of the same voltage class, performing the current reduction simulation of the low voltage class;

step (9), screening out all 10kV line models with connection relation with the line model to be overhauled during the low-voltage level current reduction simulation, and defining the line model to be transformed into the 10kV line model; sequencing the to-be-transferred 10kV line models according to the importance degree of the load carried by the electrical equipment in the actual grid structure of the corresponding regional power grid, and judging the to-be-transferred 10kV line models with high importance degree of the load; in the judging process, closing a loop closing switch model of an open loop point in a to-be-transferred 10kV line model, modifying the state of the switch model in an original loop model between two 35kV power supply bus models corresponding to two ends of the to-be-transferred 10kV line model to be opened, then forming a new loop model, and carrying out loop calculation of the corresponding loop model; if the current value of the loop model does not exceed the allowable temperature rise current, defining a new loop model as a loop closing loop model, and if the current value of the loop model exceeds the allowable temperature rise current, judging the next to-be-transferred 10kV line model until the current value of the loop model does not exceed the allowable temperature rise current;

step (11), calculating the loop closing loop model through simulation through a loop calculation module, generating an analysis report and sending the analysis report to an operator, wherein the analysis report comprises a structure diagram of the loop closing loop model finally through simulation, and the structure diagram of the loop closing loop model comprises protection constant value adjustment suggestions and states of all switch models; an operator can select a closed loop transfer supply line during maintenance according to the analysis report, and adjust the switch state and the protection fixed value in the line according to the analysis report so as to realize closed loop transfer supply.

The invention has the beneficial effects that: according to the actual grid structure of the regional power grid, a tide simulation diagram is drawn, and can be separately archived by taking each 220kV transformer as a unit, so that the tide simulation diagram is convenient to take at any time; the tide simulation diagram on the simulation platform can realize more visual data graphical display, and is convenient for operators to observe and read data; different tide simulation graphs can be called according to the needs, corresponding topological structure simulation can be carried out, data and the like can be adjusted according to the needs, and the simulation is more flexible. The simulation platform is mainly used for realizing simulation of the phase angle difference power distribution network closed-loop and the non-phase angle difference power distribution network closed-loop by taking each 220kV transformer as a unit, directly obtaining a simulation result, ensuring high accuracy and intuitionism, enabling an operator to complete the operation of preparing the closed-loop without error only by operating according to the simulation result, providing technical support for the reliability of a power grid, effectively solving the problems that the existing phase angle difference power distribution network closed-loop is manually calculated and analyzed by the technician, conclusion error is large, analysis result is simple and has little significance to actual operation, and power grid accidents and risks are easy to occur by operating according to the analysis result.

The invention will be described in more detail below with reference to the drawings and examples.

Drawings

Fig. 1 is a schematic diagram of a power flow simulation diagram.

FIG. 2 is a schematic diagram of an interface of a simulation platform according to the present invention.

Fig. 3 is a partial enlarged view of fig. 2.

Fig. 4 is a schematic diagram of the simulation platform interface according to the present invention when performing loop calculation.

Fig. 5 is a schematic diagram of the simulation platform interface according to the present invention when displaying the loop calculation result.

Fig. 6 is a schematic diagram showing the display of advice information when the simulation platform interface according to the present invention displays the loop calculation result.

Fig. 7 is a schematic diagram showing a simulation diagram of a current flow simulation diagram when a problem exists after circulation calculation is performed on a simulation platform interface according to the present invention.

Detailed Description

1-7, a closed-loop simulation platform of a power distribution network with phase angle difference comprises a drawing function module and a circulation calculation module, wherein the drawing function module comprises a drawing interface and an electrical equipment model adding module, starting power supply points at the middle and low voltage sides of each 220kV transformer model, adding corresponding electrical equipment models to the drawing interface through the electrical equipment model adding module according to the actual grid structure of a regional power grid, setting parameters and states of each electrical equipment model and connecting the parameters and states with each other according to the actual grid structure of the regional power grid, and finally drawing a power flow simulation diagram taking the middle and low voltage sides of each 220kV transformer model as the starting power supply points; the tide simulation diagram comprises all 110kV line models connected with medium voltage measurement of a 220kV transformer model and all 35kV line models connected with the low voltage side of the 220kV transformer model; 110kV transformer models connected with all 110kV line models, 10kV line models and 35kV line models connected with each 110kV transformer model; a 35 transformer model connected to each 35kV line model, and a 10kV line model connected to the 35kV transformer model; and all the switch models on the 110kV line model, the 35kV line model, the 10kV line model and other electrical equipment models.

The electrical equipment model adding module can be used for adding, deleting and editing electrical equipment models, wherein the electrical equipment models comprise bus bars, wires, double-coil transformers, three-coil transformers, generators, loads, transformer stations, capacitors, series reactors, parallel reactors, switches, bus connecting wires, bypass bus PT, meter ground, grounding disconnecting links, PT, charged capacitor surfaces, fused PT, double-coil PT, lightning arresters and 35kVPT, and also comprise text; the parameters can be set by selecting the required electrical equipment model and then adding the model to the drawing interface.

After the tide simulation picture is finished, the tide simulation picture can be calculated through the circulation calculation module, if the tide simulation picture is wrong, the wrong place is displayed after calculation, and if any electric equipment model is not connected to the bus, the model setting has problems and the like. Reference may be made to fig. 7.

The 110kV and below power supply system adopts an open-loop operation mode of a power grid loop model structure, when maintenance is needed, the open-loop operation mode is closed-loop operation through a switch model of a closed open-loop point, and at the moment, a loop model is formed; by closing the switch model of each open loop point in each 220kV partition tidal current graph, each different loop model can be formed; the loop calculation module can calculate the corresponding loop model current of each loop model; the method comprises a 35kV loop model with phase angle difference and other loop models without phase angle difference;

when the circulation calculation module calculates, the circulation calculation module mainly comprises: in each loop model, comparing the current value and the current phase of each electrical equipment model with the protection fixed value of the electrical equipment model, and generating an analysis report; in the analysis report, whether the protection fixed value of each electric equipment model needs to be adjusted or not is pointed out; when the protection fixed value of the electrical equipment model is larger than the current value, adjustment is not needed; when the protection fixed value of the electrical equipment model is smaller than or equal to the current value, the protection fixed value is required to be increased;

when the circulation calculation module calculates, the method further comprises the following steps: according to the resistance and inductance of the loop model to the electrical equipment model, calculating an impact current value when the open loop point is closed, comparing the impact current value with the rated current value of each electrical equipment model, judging whether the safe operation of the equipment is affected, and displaying the result in an analysis report.

The analysis report also comprises a corresponding tide simulation graph, and the analysis report shows that the corresponding tide simulation graph is consistent with the loop model calculated by the loop calculation module.

The intelligent simulation method for the phase angle difference solution loop of the power distribution network is characterized by comprising the following steps of: the method comprises the following steps:

according to an actual grid structure of a regional power grid, using 220kV transformers as units, adding corresponding electric equipment models to a drawing interface one by one through an electric equipment model adding module on the drawing interface of a simulation platform, completing interconnection and parameter setting of the electric equipment models according to the actual grid structure, and finally drawing a tide simulation diagram taking the middle and low voltage sides of each 220kV transformer model as initial power supply points; the tide simulation diagram comprises all 110kV line models connected with medium voltage measurement of a 220kV transformer model and all 35kV line models connected with the low voltage side of the 220kV transformer model; 110kV transformer models connected with all 110kV line models, 10kV line models and 35kV line models connected with each 110kV transformer model; a 35 transformer model connected to each 35kV line model, and a 10kV line model connected to the 35kV transformer model; and all the switch models on the 110kV line model, the 35kV line model, the 10kV line model and other electrical equipment models; each 220kV transformer in the actual grid structure of the regional power grid corresponds to one tide simulation diagram, and each tide simulation diagram is named and stored independently; the input of parameters comprises resistance and inductance;

step (2), according to the real-time value of the actual grid structure of the regional power grid, recording the voltage value and the load value of each electrical equipment model in the tide simulation diagram in real time;

step (3), defining all types of switch models in each tide simulation graph according to an actual grid structure of the regional power grid, wherein the switch model types comprise four types of a loop-opening switch model, a loop-closing switch model, a standby loop-opening switch model and a common switch model; setting the states of each switch model, wherein the switch model states comprise an operation state, a hot standby state and a cold standby state;

setting current protection fixed values of all the switch models in each tide simulation graph, respectively setting three sections of current protection fixed values of each switch model, and setting names, fixed value values, protection action time and tide direction of each section of current protection fixed values;

step (5), carrying out uninterrupted load power supply transfer simulation operation according to the condition of maintenance arrangement; firstly, a corresponding tide simulation diagram is found out, and simulation operation is carried out in the corresponding tide simulation diagram;

if the to-be-overhauled line model is a 35kV line model, firstly, respectively adjusting the types of two switch models at two sides of the to-be-overhauled line model into a loop-opening switch model and a standby loop-opening switch model;

step (6), modifying the state of a closed-loop switch model of an open-loop point on a circuit model of the same voltage class directly connected with the circuit model to be overhauled into a closed state to form a loop model;

step (7), obtaining a loop model current value of the loop model in the step (6) through a loop calculation function of the system, comparing the loop model current value with the current carrying capacity of a transformer model and a wire model in a tide simulation diagram, and if the current carrying capacity exceeds the current carrying capacity, performing current reduction simulation;

step (8), during current reduction simulation, firstly performing current reduction simulation of the same voltage level, screening out all 35kV line models which have topological connection relation with the loop model, and defining the 35kV line models as to-be-transferred 35kV line models; according to the principle of distance, judging whether the corresponding 35kV line model is suitable for current reduction simulation of the same voltage level in sequence; when judging, firstly, adjusting the state of a loop closing switch model on an open loop point on a to-be-transferred 35kV line model led out by another 110kV transformer model to be closed, then adjusting the state of a switch model on the 35kV line model led out by the 110kV transformer model on the original loop model to be open to form a new loop model, and then carrying out loop calculation;

when the current value of the obtained loop model does not exceed the temperature rise current value, finishing the current reduction simulation of the same voltage class, and positioning and closing a new loop model formed by the to-be-transferred 35kV line model and the corresponding 110kV transformer model;

if the obtained loop model current value exceeds the temperature rise current value, judging that the 35kV power supply circuit is not suitable for the current reduction simulation of the same voltage level, and judging the 35kV power supply circuit at the next distance until the 35kV power supply circuit suitable for the current reduction simulation of the same voltage level is encountered; if all 35kV power supply circuits are not suitable for the current reduction simulation of the same voltage class, performing the current reduction simulation of the low voltage class;

step (9), screening out all 10kV line models with connection relation with the line model to be overhauled during the low-voltage level current reduction simulation, and defining the line model to be transformed into the 10kV line model; sequencing the to-be-transferred 10kV line models according to the importance degree of the load carried by the electrical equipment in the actual grid structure of the corresponding regional power grid, and judging the to-be-transferred 10kV line models with high importance degree of the load; in the judging process, closing a loop closing switch model of an open loop point in a to-be-transferred 10kV line model, modifying the state of the switch model in an original loop model between two 35kV power supply bus models corresponding to two ends of the to-be-transferred 10kV line model to be opened, then forming a new loop model, and carrying out loop calculation of the corresponding loop model; if the current value of the loop model does not exceed the allowable temperature rise current, defining a new loop model as a loop closing loop model, and if the current value of the loop model exceeds the allowable temperature rise current, judging the next to-be-transferred 10kV line model until the current value of the loop model does not exceed the allowable temperature rise current;

step (11), calculating the loop closing loop model through simulation through a loop calculation module, generating an analysis report and sending the analysis report to an operator, wherein the analysis report comprises a structure diagram of the loop closing loop model finally through simulation, and the structure diagram of the loop closing loop model comprises protection constant value adjustment suggestions and states of all switch models; an operator can select a closed loop transfer supply line during maintenance according to the analysis report, and adjust the switch state and the protection fixed value in the line according to the analysis report so as to realize closed loop transfer supply.

In the description of the present invention, it should be understood that the terms "center," "lateral," "upper," "lower," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of the invention and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more. In addition, the term "include" and any variations thereof are intended to cover a non-exclusive inclusion.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

The invention is described above by way of example with reference to the accompanying drawings. It will be clear that the invention is not limited to the embodiments described above. As long as various insubstantial improvements are made using the method concepts and technical solutions of the present invention; or the invention is not improved, and the conception and the technical scheme are directly applied to other occasions and are all within the protection scope of the invention.

Claims (1)

1. Take phase angle difference distribution network to close and separate ring simulation platform, its characterized in that: the system comprises a drawing function module and a circulation calculation module, wherein the drawing function module comprises a drawing interface and an electrical equipment model adding module, starting power supply points at the middle and low voltage sides of each 220kV transformer model, adding the corresponding electrical equipment model to the drawing interface through the electrical equipment model adding module according to the actual grid structure of a regional power grid, setting parameters and states of each electrical equipment model and connecting the parameters and states with each other according to the actual grid structure of the regional power grid, and finally drawing a power flow simulation diagram taking the middle and low voltage sides of each 220kV transformer model as the starting power supply points; the tide simulation diagram comprises all 110kV line models connected with medium voltage measurement of a 220kV transformer model and all 35kV line models connected with the low voltage side of the 220kV transformer model; 110kV transformer models connected with all 110kV line models, 10kV line models and 35kV line models connected with each 110kV transformer model; a 35kV transformer model connected with each 35kV line model, and a 10kV line model connected with the 35kV transformer model; all 110kV line models, 35kV line models and switch models on 10kV line models; other electrical equipment models are also included;

the 110kV and below power supply system adopts an open-loop operation mode of a power grid loop model structure, when maintenance is needed, the open-loop operation mode is used for realizing closed-loop operation through a switch model of a closed-loop point in order to ensure the continuous power supply requirement of a user, and a loop model is formed at the moment; by closing the switch model of each open loop point in each 220kV partition tidal current graph, each different loop model can be formed; the loop calculation module can calculate the corresponding loop model current of each loop model; the method comprises a 35kV loop model with phase angle difference and other loop models without phase angle difference;

when the circulation calculation module calculates, the circulation calculation module mainly comprises: in each loop model, comparing the current value and the current phase of each electrical equipment model with the protection fixed value of the electrical equipment model, and generating an analysis report; in the analysis report, whether the protection fixed value of each electric equipment model needs to be adjusted or not is pointed out; when the protection fixed value of the electrical equipment model is larger than the current value, adjustment is not needed; when the protection fixed value of the electrical equipment model is smaller than or equal to the current value, the protection fixed value is required to be increased;

when the circulation calculation module calculates, the method further comprises the following steps: according to the resistance and inductance of the loop model to the electrical equipment model, calculating an impact current value when the open loop point is closed, comparing the impact current value with the rated current value of each electrical equipment model, judging whether the safe operation of the equipment is affected, and displaying the result in an analysis report;

the analysis report also comprises a corresponding tide simulation diagram, and the analysis report shows that the corresponding tide simulation diagram is consistent with the loop model calculated by the loop calculation module;

the power distribution network combined-solution loop simulation platform with the phase angle difference further comprises a simulation method, and the simulation method comprises the following steps:

according to an actual grid structure of a regional power grid, using 220kV transformers of 220kV transformer substations as units, adding corresponding electric equipment models to a drawing interface one by one through an electric equipment model adding module on the drawing interface of a simulation platform, completing interconnection and parameter setting of the electric equipment models according to the actual grid structure, and finally drawing a tide simulation diagram taking the middle and low voltage sides of each 220kV transformer model as initial power supply points; the tide simulation diagram comprises all 110kV line models connected with medium voltage measurement of a 220kV transformer model and all 35kV line models connected with the low voltage side of the 220kV transformer model; 110kV transformer models connected with all 110kV line models, 10kV line models and 35kV line models connected with each 110kV transformer model; a 35 transformer model connected to each 35kV line model, and a 10kV line model connected to the 35kV transformer model; all the 110kV line models, the 35kV line models and the switch models on the 10kV line models also comprise other electrical equipment models;

each 220kV transformer in the actual grid structure of the regional power grid corresponds to one tide simulation diagram, and each tide simulation diagram is named and stored independently; the input of parameters comprises resistance and inductance;

step (2), according to the real-time value of the actual grid structure of the regional power grid, recording the voltage value and the load value of each electrical equipment model in the tide simulation diagram in real time;

step (3), defining all types of switch models in each tide simulation graph according to an actual grid structure of the regional power grid, wherein the switch model types comprise four types of a loop-opening switch model, a loop-closing switch model, a standby loop-opening switch model and a common switch model; setting the states of each switch model, wherein the switch model states comprise an operation state, a hot standby state and a cold standby state;

setting current protection fixed values of all the switch models in each tide simulation graph, respectively setting three sections of current protection fixed values of each switch model, and setting names, fixed value values, protection action time and tide direction of each section of current protection fixed values;

step (5), carrying out uninterrupted load power supply transfer simulation operation according to the condition of maintenance arrangement; firstly, a corresponding tide simulation diagram is found out, and simulation operation is carried out in the corresponding tide simulation diagram;

if the to-be-overhauled line model is a 35kV line model, firstly, respectively adjusting the types of two switch models at two sides of the to-be-overhauled line model into a loop-opening switch model and a standby loop-opening switch model;

step (6), modifying the state of a closed-loop switch model of an open-loop point on a circuit model of the same voltage class directly connected with the circuit model to be overhauled into a closed state to form a loop model;

step (7), obtaining a loop model current value of the loop model in the step (6) through a loop calculation function of the system, comparing the loop model current value with the current carrying capacity of all transformer models and circuit models in the power flow simulation diagram, and if the current carrying capacity exceeds the current carrying capacity, performing current reduction simulation;

step (8), during current reduction simulation, firstly performing current reduction simulation of the same voltage level, screening out all 35kV line models which have topological connection relation with the loop model, and defining the 35kV line models as to-be-transferred 35kV line models; according to the principle of distance, judging whether the corresponding 35kV line model is suitable for current reduction simulation of the same voltage level in sequence; when judging, firstly, adjusting the state of a loop closing switch model on an open loop point on a to-be-transferred 35kV line model led out by another 110kV transformer model to be closed, then adjusting the state of a switch model on the 35kV line model led out by the 110kV transformer model on the original loop model to be open to form a new loop model, and then carrying out loop calculation;

when the current value of the obtained loop model does not exceed the temperature rise current value, finishing the current reduction simulation of the same voltage class, and positioning and closing a new loop model formed by the to-be-transferred 35kV line model and the corresponding 110kV transformer model;

if the obtained loop model current value exceeds the temperature rise current value, judging that the 35kV power supply circuit is not suitable for the current reduction simulation of the same voltage level, and judging the 35kV power supply circuit at the next distance until the 35kV power supply circuit suitable for the current reduction simulation of the same voltage level is encountered; if all 35kV power supply circuits are not suitable for the current reduction simulation of the same voltage class, performing the current reduction simulation of the low voltage class;

step (9), screening out all 10kV line models with connection relation with the line model to be overhauled during the low-voltage level current reduction simulation, and defining the line model to be transformed into the 10kV line model; sequencing the to-be-transferred 10kV line models according to the importance degree of the load carried by the electrical equipment in the actual grid structure of the corresponding regional power grid, and judging the to-be-transferred 10kV line models with high importance degree of the load; in the judging process, closing a loop closing switch model of an open loop point in a to-be-transferred 10kV line model, modifying the state of the switch model in an original loop model between two 35kV power supply bus models corresponding to two ends of the to-be-transferred 10kV line model to be opened, then forming a new loop model, and carrying out loop calculation of the corresponding loop model; if the current value of the loop model does not exceed the allowable temperature rise current, defining a new loop model as a loop closing loop model, and if the current value of the loop model exceeds the allowable temperature rise current, judging the next to-be-transferred 10kV line model until the current value of the loop model does not exceed the allowable temperature rise current;

step (11), calculating the loop closing loop model through simulation through a loop calculation module, generating an analysis report and sending the analysis report to an operator, wherein the analysis report comprises a structure diagram of the loop closing loop model finally through simulation, and the structure diagram of the loop closing loop model comprises protection constant value adjustment suggestions and states of all switch models; an operator can select a closed loop transfer supply line during maintenance according to the analysis report, and adjust the switch state and the protection fixed value in the line according to the analysis report so as to realize closed loop transfer supply.