CN114638522B - Comprehensive energy system safety analysis method and system considering uncertain source and load - Google Patents

Abstract

The invention discloses a comprehensive energy system safety analysis method and system for accounting for uncertain source and load. The method comprises the following steps: step S1, establishing a steady-state model of a comprehensive energy system; s2, acquiring a state variable and a control variable current value in the comprehensive energy system and a source and charge uncertainty prediction value in the control variable; step S3, calculating the change values of the source and the charge uncertainty based on the current values and the predicted values of the source and the charge uncertainty in the control variable; s4, calculating a state variable-control variable sensitivity matrix based on the steady-state model, the control mode and the current values of the state variable and the control variable of the comprehensive energy system; and S5, calculating vulnerability indexes of the state variables based on the state variable-control variable sensitivity matrix and the source and charge uncertainty variable change values, and identifying the vulnerability state variables based on the vulnerability indexes. The invention can effectively identify the fragile state variable under the influence of the source and the charge uncertainty, and improves the safe operation level of the comprehensive energy system.

Description

Comprehensive energy system safety analysis method and system considering uncertain source and load

Technical Field

The invention belongs to the field of application of comprehensive energy systems, and particularly relates to a comprehensive energy system safety analysis method and system considering uncertain amounts of sources and charges.

Background

Along with the continuous expansion of the application range of the comprehensive energy system, the comprehensive energy system is not only connected with different types of energy flows, but also connected with uncertain amount of source side such as photovoltaic, wind power and the like and uncertain amount of load side such as electric load, thermal load, gas load and the like, so that the uncertainty of the uncertain amount of source and load can influence the state parameters of each energy flow network in the comprehensive energy system. If the photovoltaic output suddenly decreases, the output of the combined heat and power unit in the comprehensive energy system increases, and the consumed natural gas flow increases, so that the gas pressure in the natural gas network is reduced, and when the gas pressure is reduced too much, the natural gas network is easy to be unstable. How to effectively identify all fragile state variables in the comprehensive energy system under the influence of the source and the charge uncertainty is an important technical problem for improving the safe operation level of the comprehensive energy system.

Disclosure of Invention

The invention aims to provide a comprehensive energy system safety analysis method and system considering source and charge uncertainty, so as to effectively identify fragile state variables in the comprehensive energy system under the influence of the source and charge uncertainty and improve the safety operation level of the comprehensive energy system.

In order to solve the technical problems, the invention provides a comprehensive energy system safety analysis method for accounting for uncertain source and load, which comprises the following steps:

step S1, establishing a comprehensive energy system steady-state model which is composed of an electric power network steady-state model, a natural gas network steady-state model, a thermal network steady-state model and a coupling equipment steady-state model;

S2, acquiring a state variable and a control variable current value in the comprehensive energy system and a source and charge uncertainty prediction value in the control variable; the state variables include: amplitude and phase angle of voltage at each unbalanced power node, inlet temperature of each thermal load, return water temperature of each heat source, natural gas flow in each natural gas branch and pressure of each natural gas node; the control variables include: active power and reactive power consumed by electrical loads at each power node, active power and reactive power generated by conventional generator sets and renewable energy sets at each unbalanced power node, voltage amplitude and phase angle at balanced power nodes, hot water flow in each thermodynamic branch, water supply temperature of each heat source, outlet temperature of each heat load, natural gas flow consumed by each unbalanced natural gas node, and natural gas pressure at balanced natural gas nodes; The source and charge uncertainty in the control variable comprises: active power and reactive power consumed by the electric load at each power node, active power and reactive power generated by the renewable energy unit at each unbalanced power node, outlet temperature of each heat load and natural gas flow consumed by each unbalanced natural gas node; the common set of all state variables is denoted as omega ₁, the number of state variables in omega ₁ is denoted as N ₁, the 1 st state variable in omega ₁ is denoted as SV _i1, the value range of i1 is 1 to N ₁, and the current value of SV _i1 is SV _i1 _Pr; The set formed by all the control variables is recorded as omega ₂, the number of the control variables in omega ₂ is recorded as N ₂, the i2 th control variable in omega ₂ is recorded as CV _i2, The value range of i2 is 1 to N ₂, and the current value of CV _i2 is CV _i2 _Pr; The set formed by all sources and uncertain charges is recorded as omega ₃, the number of the sources and uncertain charges in omega ₃ is recorded as N ₃, and the i3 rd source in omega ₃, The number of the uncertain charge amount in omega ₂ is index_i3, the value range of i3 is 1 to N ₃, the current value of the ith 3 source and the uncertain charge amount is CV _{Index_i3} _Pr, and the predicted value of the ith 3 source and the uncertain charge amount is CV _{Index_i3} _Fu;

step S3, calculating the change values of the source and the charge uncertainty based on the current values and the predicted values of the source and the charge uncertainty in the control variable;

s4, calculating each state variable-control variable sensitivity matrix based on the steady-state model, the control mode, the state variable and the current value of the control variable of the comprehensive energy system;

And S5, calculating vulnerability indexes of the state variables based on the sensitivity matrix of the state variables and the control variables and the change values of the source and charge uncertainty, and identifying the vulnerability state variables in the comprehensive energy system based on the vulnerability indexes.

Further, the step S3 specifically includes the following steps:

the calculation method for recording the change value of the i3 source and the charge uncertainty as DeltaCV _{Index_i3},ΔCV_{Index_i3} is as follows:

ΔCV_{Index_i3}＝CV_{Index_i3}_Fu-CV_{Index_i3}_Pr

further, the step S4 specifically includes:

When the comprehensive energy system adopts a heat and electricity control mode, deducing a heat load inlet temperature-heat load outlet temperature sensitivity matrix, a natural gas node pressure-unbalanced natural gas node consumed natural gas flow sensitivity matrix, a natural gas node pressure-heat load outlet temperature sensitivity matrix, an amplitude of voltage at an unbalanced power node-active power sensitivity matrix of electric load consumption, an amplitude of voltage at an unbalanced power node-active power sensitivity matrix generated by a renewable energy unit and a calculation formula of the amplitude of voltage at the unbalanced power node-heat load outlet temperature sensitivity matrix based on the power network steady-state model, the natural gas network steady-state model, the thermodynamic network steady-state model and the coupling equipment steady-state model which are established in the step S1; let the sensitivity expression of the i1 st state variable SV _i1 relative to the i2 nd control variable CV _i2 be SF1 _i1,i2; bringing the current values of the state variables and the control variables obtained in the step S2 into calculation formulas of the sensitivities in each sensitivity matrix, obtaining specific values of elements in each sensitivity matrix and marking the specific values as SF1 _i1,i2|(SV_i1_Pr,CV_i2 _Pr);

When the integrated energy system adopts an electric fixed heat control mode, deducing a heat load inlet temperature-heat load outlet temperature sensitivity matrix, a heat load inlet temperature-electric load consumption active power sensitivity matrix, a heat load inlet temperature-renewable energy unit generated active power sensitivity matrix, a natural gas node pressure-unbalanced natural gas node consumed natural gas flow sensitivity matrix, a natural gas node pressure-electric load consumed active power sensitivity matrix, a natural gas node pressure-renewable energy unit generated active power sensitivity matrix, an unbalanced power node voltage-electric load generated active power sensitivity matrix and a non-balanced power node voltage magnitude-electric load generated active power sensitivity matrix according to the power network steady state model, the power network steady state model and the coupling equipment steady state model which are established in the step S1; let the sensitivity expression of the i1 st state variable SV _i1 relative to the i2 nd control variable CV _i2 be SF2 _i1,i2; and (3) bringing the current values of the state variables and the control variables obtained in the step (S2) into calculation formulas of the sensitivities in each sensitivity matrix, obtaining specific values in each sensitivity matrix and marking the specific values as SF2 _i1,i2|(SV_i1_Pr,CV_i2 _Pr).

Further, the step S5 specifically includes the following steps:

when the comprehensive energy system adopts a heat setting electric control mode, the identification method of the fragile state variable in the comprehensive energy system specifically comprises the following steps:

An index indicating how hard the state variable is at a lower limit due to a change value of a source or an uncertainty amount of charge is defined as a lower limit vulnerability index of the state variable, and the lower limit vulnerability index is larger and the lower limit is easier. The lower limit vulnerability index for the i1 st state variable SV _i1 is noted as VI_Down1 _i1,VI_Down1_i1, and the calculation method is as follows:

Wherein, SV _i1 _Min is the lower limit value of the state variable SV _i1, which is given by the operator of the integrated energy system; SF1 _{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3} _pr) and Δcv _{Index_i3} satisfy the following relationship:

SF1_{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3}_Pr)·ΔCV_{Index_i3}＜0

comparing the lower limit vulnerability index of each state variable if VI_Down1 _j meets The jth state variable SV _j is a fragile state variable that is easiest to lower limit under the current state of the integrated energy system when the source and the uncertainty of the charge are considered;

An index indicating how hard the state variable is up to the variable value of the source or the uncertainty amount of the load is defined as an up-to-the-limit vulnerability index of the state variable, and the higher the up-to-the-limit vulnerability index is, the easier the up-to-the-limit is. The calculation method for the upper limit vulnerability index VI_Up1 _i1,VI_Up1_i1 of the i1 state variable SV _i1 is as follows:

Wherein, SV _i1 _Max is the upper limit value of the state variable SV _i1, and is given by the operator of the comprehensive energy system; SF1 _{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3} _pr) and Δcv _{Index_i3} satisfy the following relationship:

SF1_{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3}_Pr)·ΔCV_{Index_i3}＞0

comparing the upper limit vulnerability index of each state variable if VI_Up1 _k satisfies The kth state variable SV _k is the vulnerable state variable that is easiest to get higher than the upper limit under the current state of the integrated energy system when the source and the uncertainty of the charge are considered;

when the comprehensive energy system adopts an electric fixed heat control mode, the identification method of the fragile state variable in the comprehensive energy system specifically comprises the following steps:

The lower limit vulnerability index for the i1 st state variable SV _i1 is noted as VI_Down2 _i1,VI_Down2_i1, and the calculation method is as follows:

Wherein, SV _i1 _Min is the lower limit value of the state variable SV _i1, which is given by the operator of the integrated energy system; SF2 _{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3} _pr) and Δcv _{Index_i3} satisfy the following relationship:

SF2_{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3}_Pr)·ΔCV_{Index_i3}＜0

Comparing the lower limit vulnerability index of each state variable if VI_Down2 _m meets The mth state variable SV _m is the vulnerable state variable that is the easiest to lower limit under the current state of the integrated energy system when the source and the uncertainty of the charge are considered;

The calculation method for the upper limit vulnerability index VI_Up2 _i1,VI_Up2_i1 of the i1 state variable SV _i1 is as follows:

Wherein, SV _i1 _Max is the upper limit value of the state variable SV _i1, and is given by the operator of the comprehensive energy system; SF2 _{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3} _pr) and Δcv _{Index_i3} satisfy the following relationship:

SF2_{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3}_Pr)·ΔCV_{Index_i3}＞0

Comparing the upper limit vulnerability index of each state variable if VI_Up2 _n satisfies The nth state variable SV _n is the vulnerable state variable that is the easiest to get to the upper limit under the current state of the integrated energy system when the source, charge uncertainty is considered.

The invention also provides a comprehensive energy system safety analysis system for determining the uncertainty of the source and the load, which adopts the method to analyze the safety of the comprehensive energy system, and comprises the following steps: the system comprises a comprehensive energy system steady-state model unit, a data acquisition unit, a source and load uncertainty prediction unit and a safety analysis unit;

steady-state model unit of comprehensive energy system: the method is responsible for storing parameters of a steady-state model of the comprehensive energy system and upper limit values and lower limit values of various state variables;

A data acquisition unit: the method is responsible for acquiring the current values of state variables and control variables in the comprehensive energy system;

Source/load uncertainty prediction unit: the method is responsible for predicting the source and load uncertainty in the control variable of the comprehensive energy system;

Safety analysis unit: and the method is responsible for calculating the lower limit vulnerability index and the upper limit vulnerability index of each state variable in the comprehensive energy system, and identifying the state variable which is easiest to lower limit and the state variable which is easiest to upper limit under the current state of the comprehensive energy system.

The beneficial effects of the invention are as follows:

The comprehensive energy system safety analysis method considering the source and the uncertain amount of charge establishes vulnerability indexes considering the current value of the state variable, the sensitivity of the state variable-control variable, the upper limit value of the state variable and the lower limit value of the state variable at the same time, can effectively identify the influence degree of the source and the uncertain amount of charge on the safety of each state variable, and further identifies the vulnerable state variable which is easiest to get over the lower limit value and the vulnerable state variable which is easiest to get over the upper limit value in the comprehensive energy system. The fragile state variable result identified by the method can provide information of state variables which need to be monitored in a key way for comprehensive energy system operators, and the operation scheme is changed when necessary so as to improve the operation safety of the comprehensive energy system.

Drawings

FIG. 1 is a flow chart of an implementation of a comprehensive energy system safety analysis method that accounts for source, charge uncertainty;

FIG. 2 is a functional block diagram of a comprehensive energy system security analysis system that accounts for source, charge uncertainty.

Detailed Description

The invention will now be described in further detail with reference to the accompanying drawings. The drawings are simplified schematic representations which merely illustrate the basic structure of the invention and therefore show only the structures which are relevant to the invention.

Example 1

As shown in FIG. 1, the invention provides a comprehensive energy system safety analysis method for accounting for uncertain source and load, which comprises the following steps:

Step S1, establishing a comprehensive energy system steady-state model which is composed of an electric power network steady-state model, a natural gas network steady-state model, a thermal network steady-state model and a coupling equipment steady-state model; the method for constructing the model can refer to the publications such as Wang Yingrui and the like, namely an electric-heat-gas comprehensive energy system multi-energy flow calculation method, zhao Xia and the like, namely an electric-gas comprehensive energy system energy flow calculation improvement method;

S2, obtaining a state variable and a current value of a control variable in the comprehensive energy system and a predicted value of a source and a load uncertainty in the control variable (each predicted value can be obtained through prediction software configured in the existing comprehensive energy system); the state variables include: amplitude and phase angle of voltage at each unbalanced power node, inlet temperature of each thermal load, return water temperature of each heat source, natural gas flow in each natural gas branch and pressure of each natural gas node; the control variables include: active power and reactive power consumed by electrical loads at each power node, active power and reactive power generated by conventional generator sets and renewable energy sets at each unbalanced power node, voltage amplitude and phase angle at balanced power nodes, hot water flow in each thermodynamic branch, water supply temperature of each heat source, outlet temperature of each heat load, natural gas flow consumed by each unbalanced natural gas node, and natural gas pressure at balanced natural gas nodes; The source and charge uncertainty in the control variable comprises: active power and reactive power consumed by the electric load at each power node, active power and reactive power generated by the renewable energy unit at each unbalanced power node, outlet temperature of each heat load and natural gas flow consumed by each unbalanced natural gas node; the common set of all state variables is denoted as omega ₁, the number of state variables in omega ₁ is denoted as N ₁, the 1 st state variable in omega ₁ is denoted as SV _i1, The value range of i1 is 1 to N ₁, and the current value of SV _i1 is SV _i1 _Pr; The set formed by all the control variables is recorded as omega ₂, the number of the control variables in omega ₂ is recorded as N ₂, the i2 th control variable in omega ₂ is recorded as CV _i2, the value range of i2 is 1 to N ₂, and the current value of CV _i2 is CV _i2 _Pr; The set formed by all sources and uncertain charges is recorded as omega ₃, the number of the sources and uncertain charges in omega ₃ is recorded as N ₃, and the i3 rd source in omega ₃, The number of the uncertain charge amount in omega ₂ is index_i3, the value range of i3 is 1 to N ₃, the current value of the ith 3 source and the uncertain charge amount is CV _{Index_i3} _Pr, and the predicted value of the ith 3 source and the uncertain charge amount is CV _{Index_i3} _Fu;

step S3, calculating the change values of the source and the charge uncertainty based on the current values and the predicted values of the source and the charge uncertainty in the control variable;

s4, calculating each state variable-control variable sensitivity matrix based on the steady-state model, the control mode, the state variable and the current value of the control variable of the comprehensive energy system;

And S5, calculating vulnerability indexes of the state variables based on the sensitivity matrix of the state variables and the control variables and the change values of the source and charge uncertainty, and identifying the vulnerability state variables in the comprehensive energy system based on the vulnerability indexes.

The step S3 specifically includes the following steps:

the calculation method for recording the change value of the i3 source and the charge uncertainty as DeltaCV _{Index_i3},ΔCV_{Index_i3} is as follows:

ΔCV_{Index_i3}＝CV_{Index_i3}_Fu-CV_{Index_i3}_Pr

the step S4 specifically includes the following steps:

When the comprehensive energy system adopts a heat and electricity control mode, deducing a heat load inlet temperature-heat load outlet temperature sensitivity matrix, a natural gas node pressure-unbalanced natural gas node consumed natural gas flow sensitivity matrix, a natural gas node pressure-heat load outlet temperature sensitivity matrix, an amplitude of voltage at an unbalanced power node-active power sensitivity matrix of electric load consumption, an amplitude of voltage at an unbalanced power node-active power sensitivity matrix generated by a renewable energy unit and a calculation formula of the amplitude of voltage at the unbalanced power node-heat load outlet temperature sensitivity matrix based on the power network steady-state model, the natural gas network steady-state model, the thermodynamic network steady-state model and the coupling equipment steady-state model which are established in the step S1; let the sensitivity expression of the i1 st state variable SV _i1 relative to the i2 nd control variable CV _i2 be SF1 _i1,i2; bringing the current values of the state variables and the control variables obtained in the step S2 into calculation formulas of the sensitivities in each sensitivity matrix, obtaining specific values of elements in each sensitivity matrix and marking the specific values as SF1 _i1,i2|(SV_i1_Pr,CV_i2 _Pr);

When the integrated energy system adopts an electric fixed heat control mode, deducing a heat load inlet temperature-heat load outlet temperature sensitivity matrix, a heat load inlet temperature-electric load consumption active power sensitivity matrix, a heat load inlet temperature-renewable energy unit generated active power sensitivity matrix, a natural gas node pressure-unbalanced natural gas node consumed natural gas flow sensitivity matrix, a natural gas node pressure-electric load consumed active power sensitivity matrix, a natural gas node pressure-renewable energy unit generated active power sensitivity matrix, an unbalanced power node voltage-electric load generated active power sensitivity matrix and a non-balanced power node voltage magnitude-electric load generated active power sensitivity matrix according to the power network steady state model, the power network steady state model and the coupling equipment steady state model which are established in the step S1; let the sensitivity expression of the i1 st state variable SV _i1 relative to the i2 nd control variable CV _i2 be SF2 _i1,i2; and (3) bringing the current values of the state variables and the control variables obtained in the step (S2) into calculation formulas of the sensitivities in each sensitivity matrix, obtaining specific values in each sensitivity matrix and marking the specific values as SF2 _i1,i2|(SV_i1_Pr,CV_i2 _Pr). The method for calculating the sensitivity can refer to the publications such as 'research on the operation safety of the comprehensive energy system based on sensitivity analysis' published by Chen Houge and the like, and 'static sensitivity analysis of the electric-gas coupling comprehensive energy system based on a unified power flow model' published by Luo Baifeng and the like.

The step S5 specifically includes the following steps:

when the comprehensive energy system adopts a heat setting electric control mode, the identification method of the fragile state variable in the comprehensive energy system specifically comprises the following steps:

An index indicating how hard the state variable is at a lower limit due to a change value of a source or an uncertainty amount of charge is defined as a lower limit vulnerability index of the state variable, and the lower limit vulnerability index is larger and the lower limit is easier. The lower limit vulnerability index for the i1 st state variable SV _i1 is noted as VI_Down1 _i1,VI_Down1_i1, and the calculation method is as follows:

Wherein, SV _i1 _Min is the lower limit value of the state variable SV _i1, which is given by the operator of the integrated energy system; SF1 _{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3} _pr) and Δcv _{Index_i3} satisfy the following relationship:

SF1_{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3}_Pr)·ΔCV_{Index_i3}＜0

comparing the lower limit vulnerability index of each state variable if VI_Down1 _j meets The jth state variable SV _j is the vulnerable state variable that is the easiest to lower limit under the current state of the integrated energy system when the source and charge uncertainty are considered;

An index indicating how hard the state variable is up to the variable value of the source or the uncertainty amount of the load is defined as an up-to-the-limit vulnerability index of the state variable, and the higher the up-to-the-limit vulnerability index is, the easier the up-to-the-limit is. The calculation method for the upper limit vulnerability index VI_Up1 _i1,VI_Up1_i1 of the i1 state variable SV _i1 is as follows:

Wherein, SV _i1 _Max is the upper limit value of the state variable SV _i1, and is given by the operator of the comprehensive energy system; SF1 _{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3} _pr) and Δcv _{Index_i3} satisfy the following relationship:

SF1_{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3}_Pr)·ΔCV_{Index_i3}＞0

comparing the upper limit vulnerability index of each state variable if VI_Up1 _k satisfies The kth state variable SV _k is the vulnerable state variable that is easiest to get higher than the upper limit under the current state of the integrated energy system when the source and the uncertainty of the charge are considered;

when the comprehensive energy system adopts an electric fixed heat control mode, the identification method of the fragile state variable in the comprehensive energy system specifically comprises the following steps:

The lower limit vulnerability index for the i1 st state variable SV _i1 is noted as VI_Down2 _i1,VI_Down2_i1, and the calculation method is as follows:

Wherein, SV _i1 _Min is the lower limit value of the state variable SV _i1, which is given by the operator of the integrated energy system; SF2 _{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3} _pr) and Δcv _{Index_i3} satisfy the following relationship:

SF2_{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3}_Pr)·ΔCV_{Index_i3}＜0

Comparing the lower limit vulnerability index of each state variable if VI_Down2 _m meets The mth state variable SV _m is the vulnerable state variable that is the easiest to lower limit under the current state of the integrated energy system when the source and the uncertainty of the charge are considered;

The calculation method for the upper limit vulnerability index VI_Up2 _i1,VI_Up2_i1 of the i1 state variable SV _i1 is as follows:

Wherein, SV _i1 _Max is the upper limit value of the state variable SV _i1, and is given by the operator of the comprehensive energy system; SF2 _{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3} _pr) and Δcv _{Index_i3} satisfy the following relationship:

SF2_{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3}_Pr)·ΔCV_{Index_i3}＞0

Comparing the upper limit vulnerability index of each state variable if VI_Up2 _n satisfies The nth state variable SV _n is the vulnerable state variable that is the easiest to get to the upper limit under the current state of the integrated energy system when the source, charge uncertainty is considered.

Example 2

On the basis of the embodiment 1, as shown in fig. 2, the invention also provides a comprehensive energy system safety analysis system for accounting for uncertain source and load, which comprises the following parts:

steady-state model unit of comprehensive energy system: the method is responsible for storing parameters of a steady-state model of the comprehensive energy system and upper limit values and lower limit values of various state variables;

A data acquisition unit: the method is responsible for acquiring the current values of state variables and control variables in the comprehensive energy system;

Source/load uncertainty prediction unit: the method is responsible for predicting the source and load uncertainty in the control variable of the comprehensive energy system;

Safety analysis unit: and the method is responsible for calculating the lower limit vulnerability index and the upper limit vulnerability index of each state variable in the comprehensive energy system, and identifying the state variable which is easiest to lower limit and the state variable which is easiest to upper limit under the current state of the comprehensive energy system.

Claims (5)

1. The comprehensive energy system safety analysis method taking account of uncertain source and load is characterized by comprising the following steps of:

step S1, establishing a comprehensive energy system steady-state model which is composed of an electric power network steady-state model, a natural gas network steady-state model, a thermal network steady-state model and a coupling equipment steady-state model;

S2, acquiring a state variable and a control variable current value in the comprehensive energy system and a source and charge uncertainty prediction value in the control variable; the state variables include: amplitude and phase angle of voltage at each unbalanced power node, inlet temperature of each thermal load, return water temperature of each heat source, natural gas flow in each natural gas branch and pressure of each natural gas node; the control variables include: active power and reactive power consumed by electrical loads at each power node, active power and reactive power generated by conventional generator sets and renewable energy sets at each unbalanced power node, voltage amplitude and phase angle at balanced power nodes, hot water flow in each thermodynamic branch, water supply temperature of each heat source, outlet temperature of each heat load, natural gas flow consumed by each unbalanced natural gas node, and natural gas pressure at balanced natural gas nodes; The source and charge uncertainty in the control variable comprises: active power and reactive power consumed by the electric load at each power node, active power and reactive power generated by the renewable energy unit at each unbalanced power node, outlet temperature of each heat load and natural gas flow consumed by each unbalanced natural gas node; the common set of all state variables is denoted as omega ₁, the number of state variables in omega ₁ is denoted as N ₁, the 1 st state variable in omega ₁ is denoted as SV _i1, The value range of i1 is 1 to N ₁, and the current value of SV _i1 is SV _i1 _Pr; The set formed by all the control variables is recorded as omega ₂, the number of the control variables in omega ₂ is recorded as N ₂, the i2 th control variable in omega ₂ is recorded as CV _i2, the value range of i2 is 1 to N ₂, and the current value of CV _i2 is CV _i2 _Pr; The set formed by all sources and uncertain charges is recorded as omega ₃, the number of the sources and uncertain charges in omega ₃ is recorded as N ₃, and the i3 rd source in omega ₃, The number of the uncertain charge amount in omega ₂ is index_i3, the value range of i3 is 1 to N ₃, the current value of the ith 3 source and the uncertain charge amount is CV _{Index_i3} _Pr, and the predicted value of the ith 3 source and the uncertain charge amount is CV _{Index_i3} _Fu;

step S3, calculating the change values of the source and the charge uncertainty based on the current values and the predicted values of the source and the charge uncertainty in the control variable;

s4, calculating each state variable-control variable sensitivity matrix based on the steady-state model, the control mode, the state variable and the current value of the control variable of the comprehensive energy system;

And S5, calculating vulnerability indexes of the state variables based on the sensitivity matrix of the state variables and the control variables and the change values of the source and charge uncertainty, and identifying the vulnerability state variables in the comprehensive energy system based on the vulnerability indexes.

2. The method for analyzing the safety of the comprehensive energy system according to claim 1, wherein the step S3 specifically comprises the following steps:

the calculation method for recording the change value of the i3 source and the charge uncertainty as DeltaCV _{Index_i3},ΔCV_{Index_i3} is as follows:

ΔCV_{Index_i3}＝CV_{Index_i3}_Fu-CV_{Index_i3}_Pr。

3. The method for analyzing the safety of the comprehensive energy system according to claim 2, wherein the step S4 is specifically:

When the comprehensive energy system adopts a heat and electricity control mode, deducing a heat load inlet temperature-heat load outlet temperature sensitivity matrix, a natural gas node pressure-unbalanced natural gas node consumed natural gas flow sensitivity matrix, a natural gas node pressure-heat load outlet temperature sensitivity matrix, an amplitude of voltage at an unbalanced power node-active power sensitivity matrix of electric load consumption, an amplitude of voltage at the unbalanced power node-active power sensitivity matrix generated by a renewable energy unit and a calculation formula of the amplitude of voltage at the unbalanced power node-heat load outlet temperature sensitivity matrix based on the power network steady-state model, the natural gas network steady-state model, the thermodynamic network steady-state model and the coupling equipment steady-state model; let the sensitivity expression of the i1 st state variable SV _i1 relative to the i2 nd control variable CV _i2 be SF1 _i1,i2; bringing the obtained current values of the state variables and the control variables into calculation formulas of each sensitivity in each sensitivity matrix, obtaining specific values of elements in each sensitivity matrix and marking the specific values as SF1 _i1,i2|(SV_i1_Pr,CV_i2 _Pr);

When the comprehensive energy system adopts an electric fixed-heat control mode, deducing a heat load inlet temperature-heat load outlet temperature sensitivity matrix, a heat load inlet temperature-electric load consumption active power sensitivity matrix, a heat load inlet temperature-renewable energy unit generated active power sensitivity matrix, a natural gas node pressure-unbalanced natural gas node consumed natural gas flow sensitivity matrix, a natural gas node pressure-electric load consumed active power sensitivity matrix, a natural gas node pressure-renewable energy unit generated active power sensitivity matrix, an unbalanced power node voltage amplitude-electric load consumed active power sensitivity matrix and an unbalanced power node voltage amplitude-renewable energy unit generated active power sensitivity matrix according to the electric network steady-state model, and a calculation formula of the unbalanced power node voltage amplitude-renewable energy unit generated active power sensitivity matrix; let the sensitivity expression of the i1 st state variable SV _i1 relative to the i2 nd control variable CV _i2 be SF2 _i1,i2; and (3) bringing the acquired current values of the state variable and the control variable into calculation formulas of each sensitivity in each sensitivity matrix, obtaining specific values in each sensitivity matrix and marking the specific values as SF2 _i1,i2|(SV_i1_Pr,CV_i2 _Pr).

4. The method for analyzing the safety of the comprehensive energy system according to claim 3, wherein the step S5 is specifically:

when the comprehensive energy system adopts a heat setting electric control mode, the identification method of the fragile state variable in the comprehensive energy system specifically comprises the following steps:

The lower limit vulnerability index for the i1 st state variable SV _i1 is noted as VI_Down1 _i1,VI_Down1_i1, and the calculation method is as follows:

Wherein, SV _i1 _Min is the lower limit value of the state variable SV _i1, which is given by the operator of the integrated energy system; SF1 _{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3} _pr) and Δcv _{Index_i3} satisfy the following relationship:

SF1_{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3}_Pr)·ΔCV_{Index_i3}＜0

comparing the lower limit vulnerability index of each state variable if VI_Down1 _j meets The jth state variable SV _j is the vulnerable state variable that is the easiest to lower limit under the current state of the integrated energy system when the source and charge uncertainty are considered;

The calculation method for the upper limit vulnerability index VI_Up1 _i1,VI_Up1_i1 of the i1 state variable SV _i1 is as follows:

Wherein, SV _i1 _Max is the upper limit value of the state variable SV _i1, and is given by the operator of the comprehensive energy system; SF1 _{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3} _pr) and Δcv _{Index_i3} satisfy the following relationship:

SF1_{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3}_Pr)·ΔCV_{Index_i3}＞0

comparing the upper limit vulnerability index of each state variable if VI_Up1 _k satisfies The kth state variable SV _k is the vulnerable state variable that is easiest to get higher than the upper limit under the current state of the integrated energy system when the source and the uncertainty of the charge are considered;

when the comprehensive energy system adopts an electric fixed heat control mode, the identification method of the fragile state variable in the comprehensive energy system specifically comprises the following steps:

The lower limit vulnerability index for the i1 st state variable SV _i1 is noted as VI_Down2 _i1,VI_Down2_i1, and the calculation method is as follows:

Wherein, SV _i1 _Min is the lower limit value of the state variable SV _i1, which is given by the operator of the integrated energy system; SF2 _{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3} _pr) and Δcv _{Index_i3} satisfy the following relationship:

SF2_{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3}_Pr)·ΔCV_{Index_i3}＜0

Comparing the lower limit vulnerability index of each state variable if VI_Down2 _m meets The mth state variable SV _m is the vulnerable state variable that is the easiest to lower limit under the current state of the integrated energy system when the source and the uncertainty of the charge are considered;

The calculation method for the upper limit vulnerability index VI_Up2 _i1,VI_Up2_i1 of the i1 state variable SV _i1 is as follows:

Wherein, SV _i1 _Max is the upper limit value of the state variable SV _i1, and is given by the operator of the comprehensive energy system; SF2 _{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3} _pr) and Δcv _{Index_i3} satisfy the following relationship:

SF2_{i1,Index_i3}|(SV_i1_Pr,CV_{Index_i3}_Pr)·ΔCV_{Index_i3}＞0

Comparing the upper limit vulnerability index of each state variable if VI_Up2 _n satisfies The nth state variable SV _n is the vulnerable state variable that is the easiest to get to the upper limit under the current state of the integrated energy system when the source, charge uncertainty is considered.

5. A comprehensive energy system safety analysis system taking account of source and charge uncertainty, which adopts the method as set forth in any one of claims 1-4 to perform safety analysis on real-time operation states of the comprehensive energy system, wherein the system comprises: the system comprises a comprehensive energy system steady-state model unit, a data acquisition unit, a source and load uncertainty prediction unit and a safety analysis unit;

steady-state model unit of comprehensive energy system: the method is responsible for storing parameters of a steady-state model of the comprehensive energy system and upper limit values and lower limit values of various state variables;

A data acquisition unit: the method is responsible for acquiring the current values of state variables and control variables in the comprehensive energy system;

Source/load uncertainty prediction unit: the method is responsible for predicting the source and load uncertainty in the control variable of the comprehensive energy system;

Safety analysis unit: and the method is responsible for calculating the lower limit vulnerability index and the upper limit vulnerability index of each state variable in the comprehensive energy system, and identifying the state variable which is easiest to lower limit and the state variable which is easiest to upper limit under the current state of the comprehensive energy system.