CN107947182B

CN107947182B - Dynamic power flow analysis method and dynamic power flow analysis system

Info

Publication number: CN107947182B
Application number: CN201711341354.2A
Authority: CN
Inventors: 孙宏斌; 夏天; 郭庆来
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2017-12-14
Filing date: 2017-12-14
Publication date: 2021-03-30
Anticipated expiration: 2037-12-14
Also published as: CN107947182A

Abstract

The invention provides a dynamic power flow analysis method and a dynamic power flow analysis system for a multi-energy complementary comprehensive energy system, wherein the multi-energy coupling system is subjected to network analysis by constructing a dynamic power flow model of the multi-energy complementary comprehensive energy system and adopting a hybrid solving algorithm, so that the system-level analysis and calculation can be effectively supported; the state change factors of the comprehensive energy system in the time domain are considered, dynamic load flow rolling calculation based on the time domain is carried out, and the calculation accuracy is improved.

Description

Dynamic power flow analysis method and dynamic power flow analysis system

Technical Field

The invention belongs to the field of energy Internet, and relates to a dynamic power flow analysis method and a dynamic power flow analysis system for a multi-energy complementary comprehensive energy system.

Background

In recent years, a third industrial revolution characterized by the energy internet has been awaited. The energy Internet is characterized in that a power grid is used as a main body and a platform, and coupling complementation of various energy forms is carried out. The network analysis of the multi-energy coupling system is one of important research contents in the field of energy Internet, is the calculation basis and foundation for system planning, operation regulation and control and energy trading, and not only needs to consider respective energy conversion complementation of an energy supply side and an energy utilization side in the system, but also needs to consider the network balance of the multi-energy system. At present, in respective fields of traditional electricity, heat, gas and the like, analysis methods of systems are relatively mature, for example, a power system adopts load flow calculation; the thermodynamic system follows fluid and thermodynamic laws and is calculated by two equations of simultaneous water power (or steam) and heat power; the natural gas system follows the law of fluid mechanics, and the fluid mechanics equation is used for representing and calculating. In addition, with the large construction of renewable energy sources/clean energy sources such as fans, photovoltaics, CHP/CCHP and the like, the rising of active distribution networks and intelligent micro-grids, more modeling and simulation methods aiming at single equipment and small power networks are provided, and corresponding mathematical models are provided for the comprehensive utilization of a plurality of energy forms in part of micro-grid systems. Most of the models consider point balance such as energy, momentum, mass and the like mainly from the viewpoint of equipment, but do not consider network balance, and are not suitable for system-level analysis and calculation.

In contrast, documents [1] and [2] respectively study combined power flow analysis of a power grid, a natural gas network and a heat supply network, documents [3] and [4] use a network flow model to perform simulation analysis on coal, natural gas and the power grid in the united states, and these documents consider network balance and the multi-energy characteristics of the system from the system perspective, wherein the power grid part mainly considers some typical devices in the traditional alternating current power grid, and the calculation method is mainly based on the traditional newton-raphson method, and the method is not described in the prior art for complex situations that the types of power grid devices are various (such as a new energy electric field, FACTS devices and the like) or an alternating current-direct current hybrid power grid structure is adopted, and in addition, a method that a user can develop a model and access the calculation by himself is not mentioned in the prior art.

On the other hand, professional simulation software is currently used in the respective fields of electricity and heat for auxiliary analysis, such as PSASP, BPA, PSCAD and the like in the electric field, and Thermoflow, Ansys, Cycle-Tempo and the like in the heat field, but the software does not consider the coupling between multiple functions except the self field.

[1]Martinez-Mares A,Fuerte-Esquivel C R.A Unified Gas and Power Flow Analysis in Natural Gas and Electricity Coupled Networks[J].IEEE Transactions on Power Systems,2012,27(4):2156-2166.

[2]X Liu,N Jenkins,J Wu,et al.Combined Analysis of Electricity and Heat Networks.Energy Procedia,2014,61:155-159.Liu X.Combined Analysis ofElectricity and Heat Networks[D].CardiffUniversity Institute of Energy,2013.

[3]Quelhas A,Gil E,McCalley J D,et al.A Multiperiod Generalized Network Flow Model ofthe U.S.Integrated Energy System:Part I—Model Description[J].IEEE Transactions on Power Systems,2007,22(2):829-836.

[4]Quelhas A,McCalley J D.A Multiperiod Generalized Network Flow Model of the U.S.Integrated Energy System:Part II—Simulation Results[J].IEEE Transactions onPower Systems,2007,22(2):837-844.

Disclosure of Invention

In view of the above, the invention provides a dynamic power flow analysis method and a dynamic power flow analysis system for a multi-energy complementary comprehensive energy system, which can effectively support system-level analysis and calculation by constructing a dynamic power flow model of the multi-energy complementary comprehensive energy system and solving a network analysis on the multi-energy coupling system by adopting a hybrid solution algorithm.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a dynamic power flow analysis method for a multi-energy complementary comprehensive energy system comprises the following steps:

firstly, performing network topology analysis on a non-electric system abstract diagram based on a diagram theory to construct a non-electric system quasi-steady-state model;

step two, constructing a power flow model of the power system;

step three, representing each coupling device by using a power output external characteristic steady-state model or a first-order inertia dynamic model, and constructing a coupling device power output external characteristic steady-state model or a first-order inertia dynamic model for coupling between the non-electric system and the electric system;

step four, establishing a non-electric system quasi-steady-state model in the step one, a power system power flow model in the step two and a coupling equipment power output external characteristic steady-state model or a first-order inertia dynamic model in the step three in a simultaneous manner, and constructing a dynamic power flow model of the multi-energy complementary comprehensive energy system;

and step five, solving the dynamic power flow model of the four-energy complementary comprehensive energy system by adopting a hybrid solving algorithm, wherein the hybrid solving algorithm means that the non-electric system power flow model and the electric power system power flow model are respectively solved by using different iterative algorithms.

Furthermore, in the first step, the directed edges of the graph corresponding to the pipelines in the non-electric system and the connecting pieces correspond to the vertexes of the graph, each pipeline section defines the positive flow direction, the topological structure of the non-electric system is described by using a graph matrix, and the valves are used as the attached attributes of the pipelines to be calculated.

Further, the non-electric system quasi-steady-state model is composed of a non-electric system static power flow model and a non-electric system dynamic power flow model, wherein non-electric system nodes are described by adopting a steady-state equation, and non-electric system pipelines are described by adopting a dynamic equation aiming at temperature and heat state quantity

Further, the non-electrical system static power flow model is as follows:

wherein A is a correlation matrix, A_u、A_dRespectively an upper and a lower correlation matrix, B_fIs a loop matrix. M^*Is a B-stage pipeline flow column vector, Q^*The traffic column vector is fed into the node of order N,_ΔH^*is a column vector of B-stage pipeline pressure difference, Z^*Is the height difference column vector of the first and the last nodes of the B-order pipeline, T_eIs the column vector (DEG C) of the tail end temperature of the B-stage pipeline, T_nIs an N-order node temperature column vector (DEG C), Q_J ^*Is a thermal load column vector of an N-th order node, T_aIs a B-order ambient temperature array vector (DEG C), E is a B-order temperature attenuation coefficient diagonal matrix, S is a B-order pipeline resistance coefficient array vector, H_p ^*Is the pump head column vector, H_v ^*Is the column vector of the pressure difference on two sides of the valve.

Further, the non-electrical system dynamic power flow model is as follows:

wherein, A is a correlation matrix,

in order to be the upper correlation matrix,

is a lower associative matrix, B_fIs a loop matrix. M (t)^*For time t, a B-th order pipe traffic column vector (per unit value), Q (t)^*Flow into the traffic column vector (per unit value), Δ H (t), for a node of order N at time t^*Is a column vector (per unit value) of the B-stage pipeline differential pressure at T moment_e(T) is a column vector of the temperature (DEG C) at the tail end of the B-stage pipeline at the time T, and T_n(T) is the temperature column vector (DEG C) of the N-order node at the time T, T_s(t-gamma) is pipeline at t-gamma momentHead end temperature column vector (DEG C), lambda is heat conductivity column vector (W/m.K) of unit length of pipeline, A is pipeline cross section area column vector (m)²) Rho is the fluid density column vector (kg/m)³) L is the pipe length column vector (m), C_pIs the column vector of specific heat capacity (J/kg. DEG C.) of the fluid, Q_J(t)^*For a thermal load column vector (per unit value) of an N-th order node at time T, T_a(t) is a B-order ambient temperature array vector (DEG C) at the time t, S (t) is a B-order pipeline resistance coefficient array vector at the time t, and Z^*Is the column vector (per unit value) of the difference of the heights of the first and the last nodes of the B-order pipeline₀ ^*Is a column vector (per unit value), S, of the pump dead head of order B_pIs a column vector of pump resistance coefficients of the B order.

Further, the steady-state model of the external characteristic of the power output of the coupling equipment for coupling the non-electric system and the electric power system is as follows:

wherein, P_G ^*、Q_G ^*Respectively as the electric power and the thermal power of the combined power unit P_p ^*For pump electric power, η for pump efficiency, m^*Is the flow rate of fluid in the pump, H_p ^*For pump head, Q_hp ^*、Q_eb ^*、Q_c ^*Respectively the thermal power P of the heat pump, the electric boiler and the refrigerator_hp ^*、P_eb ^*、P_c ^*Respectively the electric power of the heat pump, the electric boiler and the refrigerator.

Further, a first-order inertia dynamic model of a coupling device for coupling between a non-electrical system and an electrical power system is as follows:

where τ is the time constant, s is the Laplace operator, P_G ^*、Q_G ^*Respectively as the electric power and the thermal power of the combined power unit P_p ^*For pump electric power, η for pump efficiency, m^*Is the flow rate of fluid in the pump, H_p ^*For pump head, Q_hp ^*、Q_eb ^*、Q_c ^*Respectively the thermal power P of the heat pump, the electric boiler and the refrigerator_hp ^*、P_eb ^*、P_c ^*Respectively the electric power of the heat pump, the electric boiler and the refrigerator.

Further, the dynamic power flow model of the multi-energy complementary comprehensive energy system is as follows:

wherein, F_e0 denotes a step two power system power flow model, F _h0 denotes step-non-electrical system quasi-steady state model of non-electrical system, F_ehAnd (F) 0 represents a dynamic power flow model of the multi-energy complementary comprehensive energy system.

Further, the hybrid solution algorithm comprises the following steps:

(1) and (3) a static power flow calculation process:

performing non-electric system static load flow calculation, and correcting the electric power of the coupling device through a coupling equipment power output external characteristic steady state or first-order inertia dynamic model according to the calculation result of the non-electric system convergence after the calculation is converged;

carrying out load flow calculation on the power system, and correcting the non-electric state quantity of the electric-thermal coupling device through a power output external characteristic steady state or first-order inertia dynamic model of the coupling equipment in the step three according to the electric power of the coupling device after the power system is converged and calculated;

if the electric power error of the coupling device obtained by the previous and subsequent two calculations does not meet the precision requirement, refreshing the non-electric state quantity of the electric heating coupling device and continuing to calculate until the maximum iteration number is exceeded, if so, stopping iteration, and taking the calculation result as an initial value of 0 moment of dynamic calculation;

(2) and (3) a dynamic power flow calculation process:

detecting whether disturbance exists at the moment or not, and if so, converting the disturbance amount into a non-electric system dynamic power flow model;

performing non-electric system dynamic load flow calculation, and correcting the electric power of the coupling device through a coupling equipment power output external characteristic steady state or first-order inertia dynamic model according to the calculation result of the non-electric system convergence after the calculation is converged;

carrying out load flow calculation on the power system, and correcting the non-electric state quantity of the electric-thermal coupling device through a power output external characteristic steady state or first-order inertia dynamic model of the coupling equipment according to the electric power of the coupling device after the power system is converged and calculated;

judging whether the electric power error of the coupling device obtained by the previous and subsequent calculations meets the precision requirement or exceeds the maximum iteration number, if not, refreshing the electric power of the electrothermal coupling device, and continuing to calculate; if yes, further judging whether the ending time is reached, if yes, finishing the calculation, outputting the result, and if not, entering the next time step for calculation.

Specifically, the hybrid solution algorithm adopted by the embodiment of the present invention includes the following steps:

(1) analyzing the topological relation of the multi-energy complementary comprehensive energy system to obtain an incidence matrix;

(2) performing data per unit processing on the model calculation data so as to finish the preparation of the calculation data;

(3) initializing the coupling equipment power system state quantity X when the number of initialization iterations k is equal to 0_e ^(k)And heat supply network system state quantity X_h ^(k)And the initial values are randomly assigned.

(4) Performing static power flow calculation on the heating power pipe network, judging whether the static power flow calculation is converged, and jumping to the step (5) if the static power flow calculation is converged; otherwise, the calculation is finished;

(5) correcting electric power P of coupling device according to static load flow calculation result of heating power pipe network_e ^(k)Is denoted by P_e ^(1)(k)And using electric power P of the coupling device_e ^(1)(k)Carrying out load flow calculation of the power system, and then judging whether convergence is achieved or not, if so, judging whether convergence is achievedJumping to the step (6); otherwise, the calculation is finished;

(6) electric power P of coupling device after electric power system load flow calculation convergence is recorded_e ^(2)(k)According to the electric power P of the coupling device_e ⁽² ^)(k)Correcting coupling device heat supply network state quantity X_h ^(k)(ii) a Then judging whether | P_e ^(1)(k)-P_e ^(2)(k)I < epsilon or k > k_maxWherein epsilon, k_maxTaking an empirical value; if k > k_maxIf yes, the calculation is finished; if P_e ^(1)(k)-P_e ^(2)(k)| < epsilon and k is less than or equal to k_maxSkipping to step (7) to perform dynamic calculation, and setting the current time t as t + dt, where dt represents a measure of one time step; otherwise, returning to the step (4) after k is k + 1;

(7) judging whether disturbance exists or not, if so, processing disturbance information and updating the state quantity X of the heat supply network_h ^(k)Then, jumping to the step (8); otherwise, directly jumping into the step (8);

(8) performing dynamic load flow calculation on the heat distribution pipe network, judging whether the calculation is converged, if so, jumping to the step (9), and if not, finishing the calculation;

(9) correcting electric power P of coupling device according to dynamic load flow calculation result of heating power pipe network_e ^(k)Is denoted by P_e ^(3)(k)And using electric power P of the coupling device_e ^(3)(k)Carrying out power system load flow calculation, judging whether the power system load flow calculation can be calculated and converged, if so, jumping to the step (10), and if not, finishing the calculation;

(10) electric power P of coupling device after electric power system load flow calculation convergence is recorded_e ^(4)(k)According to the electric power P of the coupling device_e ^(4)(k)Correcting coupling device heat supply network state quantity X_h ^(k)(ii) a Then judging whether | P_e ^(3)(k)-P_e ^(4)(k)I < epsilon or k > k_maxWherein epsilon, k_maxTaking an empirical value; if yes, jumping to a step (11); if not, returning to the step (8) after k is k + 1;

(11) judging whether t is>t_endWherein t is_endIndicates the cutoff time ifAfter the calculation is finished, outputting a calculation result; otherwise, step (7) is skipped when t is t + dt.

The invention also provides a dynamic power flow analysis system of the multi-energy complementary comprehensive energy system, which comprises a power analysis module, a non-power analysis module and a coupling analysis module, wherein the non-power analysis module is used for realizing the quasi-steady-state model of the non-power system in the first step; and the power analysis module, the non-power analysis module and the coupling analysis module realize data interaction to solve the dynamic power flow model of the multi-energy complementary comprehensive energy system in the fourth step and the fifth step.

Further, the non-power analysis module comprises two base classes of pipelines and nodes, on the basis, an equipment model class which comprises two base classes depending on the two base classes is designed and is used for referring to the same class of equipment, then a subclass model instance class of the equipment model class is designed and is used for referring to the actual equipment, a subclass model instance set class of the design model instance class is designed, and the set of each actual equipment model object is realized, so that the non-power analysis module is formed.

Furthermore, model calculation of the non-power analysis module and the coupling analysis module is independently compiled into a dynamic link library file, and the file is called through a user program interface of the existing power system simulation analysis software to realize joint calculation; the existing power system simulation analysis software is used as a power analysis module.

Further, existing power system simulation analysis software is individually compiled into an executable program as a power analysis module, and the program is executed to complete joint calculation by being embedded into model calculation programs of a non-power analysis system and a coupling analysis system.

Furthermore, a user establishes a self-defined model of the equipment through a graphical interface, the system automatically generates a model file, a dynamic link library program analyzes the model file and is internally provided with an algorithm, and mutual transmission and cooperative calculation of data are realized through an interface with a main program of the system.

Further, the access program calculation process of accessing the system main program into the user-defined model comprises the following steps:

(1) the time T is recorded as T, wherein T is the current moment, the main program completes the self dynamic load flow calculation process, after the convergence is judged to be achieved, the user-defined model is called through the user interface, the step (2) is skipped, and if the convergence cannot be achieved, the program is ended;

(2) completing the flow of the analysis, initial value assignment and load flow calculation of the self-defined model, if the load flow calculation reaches convergence, jumping to the step (3), otherwise, ending the program;

(3) and judging whether the converged output variable value meets the program ending constraint condition, namely comparing the output variable value of the converged custom model with the corresponding main program interface variable value, if the error is smaller than a set threshold value, judging that T is T + dt, and continuing the next-time step dynamic power flow calculation by the main program, otherwise, ending the program.

The invention has the beneficial effects that:

(1) according to the invention, the dynamic power flow model of the multi-energy complementary comprehensive energy system is constructed, and the hybrid solving algorithm is adopted to solve and perform network analysis on the multi-energy coupling system, so that the system-level analysis and calculation can be effectively supported; and the state change factors of the comprehensive energy system in the time domain are considered, dynamic load flow rolling calculation based on the time domain is carried out, and the calculation accuracy is improved.

(2) The invention adopts a mixed solving algorithm of different iteration methods aiming at different systems, for example, the power flow adopts an optimal multiplier method, the thermal flow adopts a Newton-Raphson method, the convergence is ensured, and the efficiency is not sacrificed.

(3) The invention adopts an embedded program development method, has openness and expandability, independently compiles model calculations of other energy form networks and coupling equipment into dynamic link library files, and the power system simulation analysis software calls the files through a user program interface to realize joint calculation or independently compiles the power system simulation analysis software into executable programs, and executes the executable programs to complete the joint calculation by embedding the executable programs into the model calculation programs of the other energy form networks and the coupling equipment.

(4) The method adopts a mode of calling a dynamic link library file to externally connect user-defined modeling, has openness and expandability, establishes a user-defined transfer function mathematical model of the equipment through a graphical interface, automatically generates a model file by a program, analyzes the model file by the dynamic link library program and embeds an algorithm, and realizes mutual transfer and cooperative calculation of data through an interface with a main program; the user-defined modeling adopts an object-oriented program architecture, and has openness and expandability.

(5) On one hand, the simulation of various power grid equipment including a direct current system, a new energy electric field, FACTS devices and the like can be performed by utilizing the calculation function of the existing mature power system simulation software, so that the workload of program development is reduced, and meanwhile, a more advanced calculation method can be adopted, so that the convergence and the reliability of calculation are ensured; on the other hand, the simulation software function of the power system is expanded, so that the simulation calculation of the multi-energy coupling system can be carried out; on the other hand, the multi-energy coupling system can be further subjected to steady-state or dynamic analysis on the basis of combined load flow calculation by relying on a powerful model library of power system simulation software, and the multi-energy coupling system has openness and expandability, so that a user-defined model can be further developed on the basis to participate in simulation calculation by a person skilled in the art, and the simulation analysis capability of the comprehensive energy system is greatly expanded.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

fig. 1 is a dynamic power flow calculation process of the multi-energy complementary comprehensive energy system provided by the invention (taking an electric heating coupling system as an example);

FIG. 2 is a diagram illustrating classes and relationships of a non-electrical system based on an object-oriented program architecture according to the present invention;

FIG. 3 is a calculation flow of the case where the main program provided by the present invention is accessed to the custom model.

Fig. 4 is a topology structure diagram of a 6-bus power system provided in an embodiment of the present invention;

FIG. 5 is a diagram of a topology of a cold net system according to an embodiment of the invention;

fig. 6 is a topology structure diagram of a heat supply network system according to an embodiment of the present invention;

FIG. 7 is a diagram illustrating the effect of the hybrid iterative solution algorithm provided by the embodiment of the present invention;

FIG. 8 is a graph of the trend of node temperature change for CCHP 2;

FIG. 9 is a graph of a heat supply network node temperature profile;

FIG. 10 is a trend graph of the output electric power of CCHP 2;

fig. 11 is a trend graph of the output thermal power of the CCHP1, 2.

Detailed Description

The present invention will be described below based on examples, but the present invention is not limited to only these examples.

The invention provides a dynamic power flow analysis method for a multi-energy complementary comprehensive energy system, which realizes network analysis of the multi-energy coupling system by calculating the dynamic power flow of the multi-energy coupling system constructed by a heat, gas, cold and other non-electric system and an electric system. The method specifically comprises the following steps:

the method comprises the following steps: construction of non-electrical system quasi-steady-state model

For convenience of description, the dynamic power flow analysis method embodiment of the present invention only describes the quasi-steady-state model of the non-electrical system provided by the present invention by taking the heat supply network as an example, the non-electrical systems such as the air and cold networks are similar to the heat supply network structure, and those skilled in the art can easily extend the quasi-steady-state model of the non-electrical system provided by the present invention to other non-electrical systems such as the air and cold networks.

The quasi-steady state model of the non-electric system refers to that nodes in a network system adopt a steady state equation, and pipelines adopt a dynamic equation aiming at temperature and heat state quantity.

The invention discloses a heat distribution network, which mainly comprises heat distribution pipelines and connecting pieces, wherein a heat distribution system is abstracted into a graph to perform network topology analysis based on graph theory, wherein the heat distribution pipelines correspond to directed edges of the graph, the connecting pieces (heat sources, heat loads and pipeline connecting pieces) correspond to vertexes of the graph, valves are used as the accessory attributes of the pipelines, each pipeline section defines the positive flow direction, for example, the flow direction of fluid during heat distribution network design is taken, and therefore, the topological structure of the heat distribution system can be described by using a matrix of the graph. The topological structure of the thermodynamic system comprises N nodes and B pipelines, and after the heat supply network is abstracted, a heat supply network incidence matrix, an upper incidence matrix, a lower incidence matrix and a loop matrix can be obtained.

(1) Static power flow model

The method comprises the steps of respectively carrying out fluid mechanics modeling and thermal working condition modeling on a heat supply network, respectively constructing a fluid mechanics steady-state equation (expressions 1 st to 3) of a thermal system and a thermal working condition steady-state equation (expressions 4 th to 5) of the thermal system, and obtaining a static power flow model of the heat supply network by combining the fluid mechanics steady-state equation and the thermal working condition steady-state equation as shown in the specification.

Wherein A is a heat supply network correlation matrix,

in order to be the upper correlation matrix,

is a lower associative matrix, B_fIs a loop matrix. M^*Is a B-stage pipeline flow column vector, Q^*The traffic column vector is fed into the node of order N,_ΔH^*is a column vector of B-stage pipeline pressure difference, Z^*Is the height difference column vector of the first and the last nodes of the B-order pipeline, T_eIs the column vector (DEG C) of the tail end temperature of the B-stage pipeline, T_nIs an N-order node temperature column vector (DEG C), Q_J ^*Is a thermal load column vector of an N-th order node, T_aIs a B-order ambient temperature array vector (DEG C), E is a B-order temperature attenuation coefficient diagonal matrix, S is a B-order pipeline resistance coefficient array vector, H₀ ^*Is the column vector of the static head of the B-order pump, S_pIs a column vector of pump resistance coefficients of the B order. T is_e、T_n、T_aThe other state quantities are per unit values for named values.

The

expressions

1 and 5 are used for calculating the non-electric system nodes, and the pipelines of the expressions 2 to 4 are used for calculating the initial value of the 0 th time of the dynamic power flow model of the pipeline formula (2).

(2) Dynamic power flow model

The dynamic power flow model for the temperature and the heat state quantity is as follows:

a is a heat supply network association matrix,

in order to be the upper correlation matrix,

is a lower associative matrix, B_fIs a loop matrix. M (t)^*For time t, a B-th order pipe traffic column vector (per unit value), Q (t)^*Flow into the traffic column vector (per unit value), Δ H (t), for a node of order N at time t^*Is a column vector (per unit value) of the B-stage pipeline differential pressure at T moment_e(T) is a column vector of the temperature (DEG C) at the tail end of the B-stage pipeline at the time T, and T_n(T) is the temperature column vector (DEG C) of the N-order node at the time T, T_s(t-gamma) is a column vector (DEG C) of the head temperature of the pipeline at the time of t-gamma, lambda is a column vector (W/m.K) of the heat conductivity of the unit length of the pipeline, and A is a column vector (m) of the cross section area of the pipeline²) Rho is the fluid density column vector (kg/m)³) L is the pipe length column vector (m), C_pIs the column vector of specific heat capacity (J/kg. DEG C.) of the fluid, Q_J(t)^*For a thermal load column vector (per unit value) of an N-th order node at time T, T_a(t) is a B-order ambient temperature array vector (DEG C) at the time t, S (t) is a B-order pipeline resistance coefficient array vector at the time t, and Z^*Is the column vector (per unit value) of the difference of the heights of the first and the last nodes of the B-order pipeline₀ ^*Is a column vector (per unit value), S, of the pump dead head of order B_pIs a column vector of pump resistance coefficients of the B order.

Step two: construction of power flow model of electric power system

The power system load flow model adopted by the invention is the prior art, the current power system load flow model and calculation are relatively mature, and a plurality of mature power system simulation software appears, such as PSASP software developed by China department of Electrical sciences, BPA software developed by American EPRI, and the like, so that the description is omitted, and only the power system load flow model formula used commonly is listed.

Wherein, P_i、Q_iInjecting active and reactive power, G, respectively, for a network node i of the power system_ij、B_ijAre the mutual conductance and susceptance, delta, between nodes i, j, respectively_ijRepresenting the phase angle difference between nodes i, j, U being the node voltage. The above are per unit values.

Step three: constructing a steady-state or first-order inertia dynamic model of external characteristics of power output of equipment coupled between a non-electric system and an electric power system

The construction of a coupling equipment model for coupling between a non-electric system and an electric system is the premise and the basis for carrying out load flow unified calculation, and an electrothermal coupling device generally comprises a combined supply unit, a water pump, a heat pump, an electric boiler, a refrigerator and the like by taking electrothermal coupling as an example. The working mechanisms in the devices are different and complex, but for the power grid and non-electric system coupling power flow calculation, the relation between the power grid power flow and the non-electric system power flow can be established by representing each coupling device by using a power output external characteristic steady-state or first-order inertia dynamic model, so that the combined solution is realized. The model is represented by the following formula, the model covers the description of all coupling equipment of electricity and non-electricity, and corresponding model calculation is carried out according to the selection of an actual coupling device in the calculation.

The output external characteristic steady-state model is shown as equation (4):

the first order inertial dynamics model is shown in equation (5):

the first-order inertia dynamic model mainly considers the time delay effect (process) from the change of independent variable to the response of dependent variable in the actual physical system, and is a common equivalent simulation. Where τ is the time constant and s is the laplacian, the model is represented by a transfer function.

In formulas (4) and (5), P_G ^*、Q_G ^*Respectively as the electric power and the thermal power of the combined power unit P_p ^*For pump electric power, η for pump efficiency, m^*Is the flow rate of fluid in the pump, H_p ^*For pump head, Q_hp ^*、Q_eb ^*、Q_c ^*Respectively the thermal power P of the heat pump, the electric boiler and the refrigerator_hp ^*、P_eb ^*、P_c ^*Respectively the electric power of the heat pump, the electric boiler and the refrigerator. The above are per unit values.

Step four: dynamic power flow model for constructing multi-energy complementary comprehensive energy system

And (3) establishing a non-electric system power flow model in the step one, a power system power flow model in the step two and a coupling equipment operation external characteristic model in the step three in a simultaneous manner, and constructing a dynamic power flow model of the multi-energy complementary comprehensive energy system as shown in the following.

Wherein, F_eThe power flow model of the power system is represented by 0, F _h0 denotes the non-electrical system quasi-steady-state model, F_ehAnd 0 represents an external characteristic model of the operation of the coupling equipment, and 0 represents a dynamic power flow model of the multi-energy complementary comprehensive energy system.

Step five: hybrid solving algorithm is adopted to solve the dynamic power flow model of the multi-energy complementary comprehensive energy system

The power system and the non-power system have obvious differences in system composition, operation mechanism, response time scale, output characteristic and the like, and the system control in the actual operation process is relatively independent. Taking electrothermal coupling as an example, the electric and thermal parts are related by electrothermal coupling equipment, and the two parts are in a loose coupling relationship. Therefore, according to the characteristic that the power system is coupled with the non-electric system, in the specific calculation process, the two parts do not need to be jointly solved in one iteration, the calculation can be independently carried out, only after the power or non-power flow is converged, the adjustment of partial state quantity is carried out according to the output characteristic equation of the coupling device, then the iterative calculation of the power flow of another energy source is carried out, and the steps are repeated to achieve the overall convergence. By the method, the problems of poor calculation convergence, long time consumption and more occupied computer memory space of the power system and the non-power system as a whole can be solved, and the computer program is easy to design and implement.

Furthermore, the hybrid solution algorithm is respectively carried out on the non-electric system and the electric system by adopting different iteration methods, for example, the optimal multiplier method is adopted for the power flow calculation of the electric system, and the Newton-Raphson method is adopted for the power flow calculation of the non-electric system, so that the faster convergence can be realized.

The dynamic power flow calculation process of the multi-energy complementary comprehensive energy system provided by the invention is shown in fig. 1, and an electrothermal coupling system is taken as an example for explanation. The method specifically comprises the following steps:

(1) analyzing the topological relation of the multi-energy complementary comprehensive energy system to obtain an incidence matrix (such as a heat supply network incidence matrix A and an upper incidence matrix A in the step one)_uLower correlation matrix A_dAnd loop matrix B_fEtc.);

(3) initializing the coupling equipment power system state quantity X when the number of initialization iterations k is equal to 0_e ^(k)＝[P^T,Q^T,U^T,δ^T]^T(the character definition is shown in step two) and the state quantity X of the heat supply network system_h ^(k)＝[M^*T,Q^*T,_ΔH^*T,T_e ^T,T_n ^T,Q_J ^*T]^T(the character definition is shown in step one) is a per unit value and is initiallyThe starting values are randomly assigned.

(5) correcting electric power P of coupling device according to static load flow calculation result of heating power pipe network_e ^(k)＝[PG^*T,P_p ^*T,Ph_p ^*T,Peb^*T,Pc^*T]^T(see step 3 for character definition) and is denoted by Pe¹)(^k) And using electric power P of the coupling device_e ^(1)(k)Carrying out power flow calculation on the power system, judging whether convergence is achieved, and if yes, jumping to the step (6); otherwise, the calculation is finished;

(6) electric power P of coupling device after electric power system load flow calculation convergence is recorded_e ^(2)(k)According to the electric power P of the coupling device_e ⁽² ^)(k)Correcting coupling device heat supply network state quantity X_h(^k) (ii) a Then judging whether | P_e ^(1)(k)-P_e ^(2)(k)I < epsilon or k > k_maxWherein epsilon, k_maxAnd taking an empirical value. If k > k_maxIf yes, the calculation is finished; if P_e ^(1)(k)-P_e ^(2)(k)| < epsilon and k is less than or equal to k_maxSkipping to step (7) to perform dynamic calculation, and setting the current time t as t + dt, where dt represents a measure of one time step; otherwise, returning to the step (4) after k is k + 1;

(9) correcting electric power P of coupling device according to dynamic load flow calculation result of heating power pipe network_e ^(k)Is denoted by P_e ^(3)(k)And using electric power P of the coupling device_e ^(3)(k)Carrying out load flow calculation of the power system, and then judging whether the load flow calculation of the power system can be carried out or notCalculating convergence, if yes, jumping to the step (10), and if not, finishing the calculation;

(11) judging whether t is>t_endWherein t is_endIndicating the cut-off time, if so, finishing the calculation, and outputting a calculation result; otherwise, step (7) is skipped when t is t + dt.

In summary, the invention first performs the static power flow calculation process: firstly, performing static power flow model calculation of a non-electric system in the step one, correcting electric power of the coupling device through a power output external characteristic steady state or first-order inertia dynamic model of the coupling device in the step three according to a calculation result of the non-electric system convergence after the calculation is converged, then performing power flow calculation of the electric power system, and correcting non-electric state quantity of the electric heating coupling device through the power output external characteristic steady state or first-order inertia dynamic model of the coupling device after the calculation is converged according to the electric power of the coupling device after the calculation is performed by the electric power system. And if the electric power error of the coupling device obtained by the two previous and subsequent calculations does not meet the precision requirement, refreshing the electric power of the electrothermal coupling device, continuing to calculate, and if so, judging whether the maximum iteration number is exceeded or not. If the maximum iteration number is exceeded, the calculation is finished, otherwise, the pure delay dynamic calculation is started.

In the pure delay dynamic calculation process, after disturbance is eliminated, non-electric state load flow calculation and power system load flow calculation are respectively carried out, the process is similar to the static load flow calculation process, and after the power error of the coupling device meets the precision requirement or reaches the maximum iteration times, when the time reaches the cut-off time, the calculation is finished, and the result is output.

The power flow calculation of the power system can be completed by existing mature power system simulation software, such as PSASP software developed by the chinese academy of electrical sciences, BPA software developed by the american EPRI, and the like, and therefore, the details are not repeated herein.

Furthermore, the non-electric system can be in any energy form of non-electric energy sources such as heat, cold and gas, for example, the heat supply network, so that the electric-heat coupling is realized.

For convenience of data interaction, simplification of calculation, improvement of convergence and convenience of result analysis, the load flow calculation of the present invention uses per unit values as described above, but the present invention is not limited to using per unit values, and includes other unit systems that can be easily conceived by those skilled in the art.

The invention also provides a dynamic power flow analysis system for the multi-energy complementary comprehensive energy system, which comprises a power analysis module, a non-power analysis module and a coupling analysis module, wherein the non-power analysis module is used for realizing the quasi-steady-state model calculation of the non-power module dynamic power flow model in the first step, the power analysis module is used for realizing the power flow calculation of the power flow model in the second step, and the coupling analysis module is used for realizing the calculation of the external characteristic steady state or the first-order inertia dynamic model of the coupling equipment between the non-power module and the power module.

And the power analysis module, the non-power analysis module and the coupling analysis module jointly realize the solving of the dynamic power flow model of the multi-energy complementary comprehensive energy system in the fourth step and the fifth step. Specifically, the dynamic power flow model parameters of the multi-energy complementary comprehensive energy system are read from the data file, and the dynamic power flow calculation process of the multi-energy complementary comprehensive energy system is executed.

The non-power analysis module is based on the design concept of a C + + object-oriented program architecture, as shown in FIG. 2, and comprises two base classes of a pipeline (pipe) and a node (node), on the basis, an equipment model class which comprises two base classes depending on the two base classes is designed and is used for referring to the same class of equipment, then a subclass model instance class of the equipment model class is designed and refers to actual equipment, a subclass model instance set class of the model instance class is designed, and the collection of model objects of each actual equipment is realized, so that the non-power analysis module is formed.

The invention adopts an embedded program development method, model calculations of a non-power analysis module and a coupling analysis module are independently compiled into a dynamic link library file, power system simulation analysis software calls the file through a user program interface of the power system simulation analysis software to realize joint calculation, and the existing mature simulation analysis software can be adopted; existing power system simulation analysis software may also be separately compiled into an executable program that is executed to perform the joint calculations by embedding in a model calculation program for the non-power analysis system and the coupled analysis system.

The mode of calling the dynamic link library file is adopted, the external connection of user-defined modeling can be realized, the openness and the expandability are realized, a user establishes a user-defined transfer function mathematical model of the equipment through a graphical interface, a program automatically generates the model file, the dynamic link library program analyzes the model file and is internally provided with an algorithm, and the mutual transfer and the cooperative calculation of data are realized through an interface with a main program.

Taking the power system simulation analysis software to call the dynamic link library file through the user program interface to realize the joint calculation, such as PSASP power system simulation analysis, the invention can utilize the function of the PSASP User Program Interface (UPI) to realize the compatibility of the PSASP with the model calculation program module of the user-defined non-power analysis system and the coupling analysis system, so that the PSASP becomes an open software package. The load flow calculation user program interface (LF/UPI) realizes the alternate operation of the power load flow calculation module and the user program module, and jointly completes a new task based on load flow calculation.

As shown in fig. 3, the access program calculation process for accessing the main program to the user-defined model includes:

The embodiment of the invention comprises the following steps:

taking a 6-bus power system connected with a cold network and a hot network as an example, as shown in fig. 4, a bus 1 is connected with an external large power grid,

buses

2 and 6 are respectively connected with two combined cooling heating and power units (hereinafter referred to as CCHP units), and

buses

3, 4 and 5 are connected with loads; in addition, the bus 3 can be connected to a wind farm and the bus 4 can be connected to a photovoltaic power station. The network topology parameters of the power system are shown in table 1 and table 2:

TABLE 1 electric Power System line parameters

TABLE 2 Transformer parameters

As shown in fig. 5 and fig. 6, the cold and hot networks are both 5-node systems, where

nodes

5 and 4 are respectively connected to the two CCHP units in fig. 4 for cooling and heating, and

nodes

1, 2, and 3 are connected to the cold and hot loads. The pipeline parameters are shown in table 3 (the water return pipeline parameters are symmetrical to the water supply pipeline):

TABLE 3 Cold/Heat network piping parameters

Thermoelectric ratio of CCHP unit:

let the CCHP1 satisfy the thermoelectric ratio:

the CCHP2 thermoelectric ratio satisfies:

wherein phi₁，Φ₂Representing the heat power, P, of the CCHP unit₁，P₂Representing the CCHP plant electric power.

The cold-heat ratio is 1.2 COP.

Let load 1 be a commercial load, load 2 be an industrial load, and load 3 be a consumer load. The power factor of the load is 0.95, and the power factor of the wind power and the photovoltaic power is 0.8.

Setting e1 as a balance node, setting e3, e4 and e5 (namely load 1, load 2 and load 3) as PQ nodes, setting e2 and e6 (namely CCHP1 and CCHP2) as PV-PQ nodes, and listing the static power flow model of the power system expressed in the step two according to the parameters, wherein n is 6, G is 6, and G is 2_ij、B_ijThe reciprocal of the resistance and reactance of each line/transformer in tables 1 and 2, i.e. the conductance and susceptance per unit value of the line and transformer, i.e. the equation F in step four_e＝0。

Then, according to the connection relation of the first node and the last node of the pipeline in the table 3, a cold/hot network incidence matrix is obtained by using a graph theory, namely, the first step A is a hot network incidence matrix,

in order to be the upper correlation matrix,

is a lower moment of correlation

Array, B_fFor the loop matrix, Q, assuming no leakage in the cold/hot network system^*When the pipes are in the same horizontal plane, Z is 0^*＝0，H₀ ^*、S_pConverting parameters of a nameplate of the pump into given values; t is_aI.e. the local ambient temperature at which the coupling device is located, is also a given value, M^*,ΔH^*,T_e ^*,T_n ^*,Q_J ^*For the required state quantity of the cold/hot network, the expression of step one can be listedIn the dynamic power flow model, the density, the pipe length, the pipe section area, the specific heat capacity and the heat conductivity are given values under the condition of determining a transmission working medium, namely an equation F in the fourth step of the formula_h＝0。

The electric heating cold coupling device in this embodiment only has CCHP1 and CCHP2, so formula 11 can be calculated only, and formula 11 in step three, namely formula P, is obtained according to the thermoelectric ratio formula and the cold-heat ratio formula of the CCHP unit^*＝f(Q_J ^*) Wherein P is^*For coupling equipment power system state quantity X_ePer unit value of electromagnetic power, Q, of the device_J ^*System state variable X for heating/cooling network system of coupling device_hThe unit value of the thermal power (thermal load, negative for CCHP) of the device in (1), that is, the equation F in step four_eh0. Therefore, a dynamic power flow model of the multi-energy complementary comprehensive energy coupling system can be obtained.

And solving according to the calculation flow of the step five. Wherein, the power system load flow calculation is handed over to the existing power system simulation software calculation; generating a dynamic link library of a corresponding model according to customer self-definition by the load flow calculation of the cold/heat network system and the load flow calculation of the coupling equipment, calling a dynamic link library file through a user program interface of the power system simulation analysis software to realize joint calculation, wherein the calculation result is X_hAnd X_eThe final converged numerical solution of (1).

For example, fig. 7 shows the results obtained by respectively adopting a unified iterative algorithm and different iterative algorithms in one time step when electric heating or electric cooling is coupled. For example, the optimal multiplier method is adopted for power system calculation, and the Newton-Raphson method is adopted for hot network and cold network calculation, and it can be seen from the figure that the hybrid solution algorithm adopting different iterative algorithms can realize faster convergence.

The node temperature of CCHP2 in this embodiment is changed slowly from 80 degrees to 100 degrees at time 10s, as shown in fig. 8, and the calculation time domain is 24 minutes. Taking an electrothermal coupling system as an example, the temperature change of the CCHP2 node brings about the influence on the states of subsequent devices of a thermodynamic system and an electric power system, because of the heat transfer delay of a pipeline, the temperature change of other nodes is changed according to the different distances from the node, the temperature change occurs successively, the output change of the combined cooling heating and power unit is changed according to the change of the temperature of the node, all the output is increased along with the temperature rise, but the output finally returns to the vicinity of the initial level because the fuel supply is not changed. Fig. 9 shows the temperature of the heat supply network node, fig. 10 shows the output electric power change curve of the CCHP2, and fig. 11 shows the output thermal power change curves of the CCHP1 and 2.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and the present invention may be variously modified and changed. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A dynamic power flow analysis method for a multi-energy complementary comprehensive energy system is characterized by comprising the following steps:

step two, constructing a power flow model of the power system;

solving the dynamic power flow model of the four-energy complementary comprehensive energy system by adopting a hybrid solving algorithm, wherein the hybrid solving algorithm is that the non-electric system power flow model and the electric power system power flow model are respectively solved by using different iterative algorithms;

the hybrid solution algorithm comprises the following steps:

(1) and (3) a static power flow calculation process:

(2) and (3) a dynamic power flow calculation process:

judging whether the electric power error of the coupling device obtained by the previous and subsequent calculations meets the precision requirement or exceeds the maximum iteration number, if not, continuing to calculate after refreshing the non-electric state quantity of the electric heating coupling device; if so, further judging whether the ending time is reached, if so, finishing the calculation and outputting a result, otherwise, entering the next time step calculation;

or the hybrid solution algorithm comprises the following steps:

(3) initializing the coupling equipment power system state quantity X when the number of initialization iterations k is equal to 0_e ^(k)And heat supply network system state quantity X_h ^(k)And the initial values are randomly distributed;

(5) correcting electric power P of coupling device according to static load flow calculation result of heating power pipe network_e ^(k)Is denoted by P_e ^(1)(k)And using electric power P of the coupling device_e ^(1)(k)Carrying out power flow calculation on the power system, judging whether convergence is achieved, and if yes, jumping to the step (6); otherwise, the calculation is finished;

(6) electric power P of coupling device after electric power system load flow calculation convergence is recorded_e ^(2)(k)According to the electric power P of the coupling device_e ^(2)(k)Correcting coupling device heat supply network state quantity X_h ^(k)(ii) a Then judging whether | P_e ^(1)(k)-P_e ^(2)(k)I < epsilon or k > k_maxWherein epsilon, k_maxTaking an empirical value; if k > k_maxIf yes, the calculation is finished; if P_e ^(1)(k)-P_e ^(2)(k)| < epsilon and k is less than or equal to k_maxSkipping to step (7) to perform dynamic calculation, and setting the current time t as t + dt, where dt represents a measure of one time step; otherwise, returning to the step (4) after k is k + 1;

2. The dynamic power flow analysis method for the multi-energy complementary comprehensive energy system according to claim 1, characterized in that: in the first step, directed edges of a graph corresponding to a pipeline in a non-electric system are used, a connecting piece corresponds to the top point of the graph, each pipeline section defines the positive direction of flow, a topological structure of the non-electric system is described by a graph matrix, and a valve is used as an attached attribute of the pipeline to be calculated.

3. The dynamic power flow analysis method for the multi-energy complementary comprehensive energy system according to claim 1, characterized in that: the non-electric system quasi-steady-state model is composed of a non-electric system static power flow model and a non-electric system dynamic power flow model, wherein non-electric system nodes are described by adopting a steady-state equation, and non-electric system pipelines are described by adopting a dynamic equation aiming at temperature and heat state quantity.

4. The dynamic power flow analysis method for the multi-energy complementary comprehensive energy system according to claim 3, characterized in that: the non-electric system static power flow model is as follows:

wherein A is a correlation matrix, A_u、A_dRespectively an upper and a lower correlation matrix, B_fIs a loop matrix; m is a flow column vector of the B-stage pipeline, Q is an inflow flow column vector of the N-stage node,_Δh is the differential pressure column vector of the B-stage pipeline, Z is the height difference column vector of the nodes at the head end and the tail end of the B-stage pipeline, T_eIs the column vector (DEG C) of the tail end temperature of the B-stage pipeline, T_nIs an N-order node temperature column vector (DEG C), Q_JIs the N-th order node heat load column vector, T_aIs a B-order ambient temperature array vector (DEG C), E is a B-order temperature attenuation coefficient diagonal matrix, S is a B-order pipeline resistance coefficient array vector, H_pIs the pump head column vector, H_vIs the column vector of the pressure difference on two sides of the valve.

5. The dynamic power flow analysis method for the multi-energy complementary comprehensive energy system according to claim 3, characterized in that: the non-electric system dynamic power flow model comprises the following steps:

wherein, A is a correlation matrix,

in order to be the upper correlation matrix,

is a lower associative matrix, B_fIs a loop matrix; m (t) is a B-stage pipeline flow column vector (per unit value) at the time t, Q (t) is an N-stage node inflow flow column vector (per unit value) at the time t,_Δh (T) is a B-stage pipeline differential pressure column vector (per unit value) at the time T, T_e(T) is a column vector of the temperature (DEG C) at the tail end of the B-stage pipeline at the time T, and T_nWhen (t) is tCarving the temperature column vector (DEG C) of the N-order node, T_s(t-gamma) is a column vector (DEG C) of the head temperature of the pipeline at the time of t-gamma, lambda is a column vector (W/m.K) of the heat conductivity of the unit length of the pipeline, and A is a column vector (m) of the cross section area of the pipeline²) Rho is the fluid density column vector (kg/m)³) L is the pipe length column vector (m), C_pIs the column vector of specific heat capacity (J/kg. DEG C.) of the fluid, Q_J(T) is the thermal load column vector (per unit value) of the Nth-order node at time T, T_a(t) is a B-order ambient temperature column vector (DEG C) at the moment t, S (t) is a B-order pipeline resistance coefficient column vector at the moment t, Z is a B-order pipeline head-end and tail-end node height difference column vector (per unit value), H₀Is the column vector (per unit value) of the static head of the B-order pump, S_pIs a column vector of pump resistance coefficients of the B order.

6. The method according to claim 1, wherein the steady state model of the external characteristic of the power output of the coupling device for coupling between the non-electric system and the electric power system is:

wherein, P_G*、Q_GRespectively as electric and thermal powers, P, of combined-supply unit_pElectrical power of the pump, efficiency of the pump, fluid flow rate in the pump, and H_pIs pump head, Q_hp*、Q_eb*、Q_cRespectively the thermal powers of heat pump, electric boiler and refrigerating machine, P_hp*、P_eb*、P_cThe power of the heat pump, the electric boiler and the refrigerator.

7. The method of claim 1, wherein the first order inertial dynamic model of the coupling device coupling the non-electrical system and the electrical system is:

where τ is the time constant, s is the Laplace operator, P_G*、Q_GRespectively as electric and thermal powers, P, of combined-supply unit_pElectrical power of the pump, efficiency of the pump, fluid flow rate in the pump, and H_pIs pump head, Q_hp*、Q_eb*、Q_cRespectively the thermal powers of heat pump, electric boiler and refrigerating machine, P_hp*、P_eb*、P_cThe power of the heat pump, the electric boiler and the refrigerator.

8. The method according to claim 1, wherein the dynamic power flow model of the multi-energy complementary integrated energy system is:

wherein, F_e0 denotes a step two power system power flow model, F_h0 denotes step-non-electrical system quasi-steady state model of non-electrical system, F_ehAnd (F) 0 represents a dynamic power flow model of the multi-energy complementary comprehensive energy system.

9. A multi-energy complementary integrated energy system dynamic power flow analysis system using the dynamic power flow analysis method according to claims 1 to 8, characterized in that: the non-electric power analysis module is used for realizing a non-electric system quasi-steady-state model in the first step, the electric power analysis module is used for realizing load flow calculation of a load flow model in the second step, and the coupling analysis module is used for realizing calculation of a coupling equipment power output external characteristic steady-state model or a first-order inertia dynamic model between the non-electric module and the electric power module; and the power analysis module, the non-power analysis module and the coupling analysis module realize data interaction to solve the dynamic power flow model of the multi-energy complementary comprehensive energy system in the fourth step and the fifth step.

10. The system according to claim 9, wherein the system further comprises: the non-power analysis module comprises two base classes of pipelines and nodes, an equipment model class which depends on the two base classes is designed on the basis and is used for referring to the same class of equipment, then a subclass model instance class of the equipment model class is designed, actual equipment is referred, a subclass model instance set class of the model instance class is designed, and the set of each actual equipment model object is realized, so that the non-power analysis module is formed.

11. The system according to claim 9, wherein the system further comprises: compiling the model calculation of the non-power analysis module and the coupling analysis module into a dynamic link library file independently, and calling the file through a user program interface of the existing power system simulation analysis software to realize joint calculation; the existing power system simulation analysis software is used as a power analysis module.

12. The system according to claim 9, wherein the system further comprises: existing power system simulation analysis software is individually compiled into an executable program as a power analysis module, and the program is executed to complete joint calculation by being embedded into model calculation programs of a non-power analysis system and a coupling analysis system.

13. The system according to claim 11 or 12, wherein the system comprises: a user establishes a self-defined model of equipment through a graphical interface, the system automatically generates a model file, a dynamic link library program analyzes the model file and is internally provided with an algorithm, and mutual transmission and cooperative calculation of data are realized through an interface with a main program of the system.

14. The system according to claim 13, wherein the process of accessing the main program of the system into the user-defined model comprises: