CN114156938B - Evaluation method for thermal power generating unit safety in wind-solar-fire coupling system - Google Patents
Evaluation method for thermal power generating unit safety in wind-solar-fire coupling system Download PDFInfo
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Abstract
The application belongs to the technical field of wind-light-fire coupling, and discloses a method for evaluating the safety of a thermal power generating unit in a wind-light-fire coupling system, which comprises the following steps: constructing a wind turbine generator power model and a photovoltaic turbine generator power model; coupling the wind turbine generator power model, the photoelectric turbine generator power model and the thermal power generating unit model to obtain a power tracking system model, and obtaining the thermal power generating unit power according to the power tracking system tracking model; obtaining the change relation of the temperature of each shaft section of the steam turbine rotor in the thermal power unit along with time according to the power of the thermal power unit, and further obtaining the fatigue loss of the rotor of the thermal power unit; the method comprises the steps of obtaining harmonic waves of a wind turbine generator and a photoelectric unit, and superposing the harmonic waves on a shafting of a thermal power unit to obtain impact of the harmonic waves on the shafting of the thermal power unit; and carrying out thermal power generating unit safety assessment based on fatigue loss and harmonic waves. The method can accurately evaluate the safety of the thermal power generating unit in the wind-solar-fire coupling system, and has very important guiding significance for the application of the thermal power generating unit.
Description
Technical Field
The application belongs to the technical field of wind-light-fire coupling, and particularly relates to an evaluation method for thermal power generating unit safety in a wind-light-fire coupling system.
Background
Electric energy plays a very important role in industrial and agricultural production and life of people, along with the rapid development of economy, the demand of various industries for electric energy is gradually increased, and in order to ensure the stability of energy supply and reduce the damage of traditional thermal power to the environment, the development and utilization of renewable energy sources form an important research direction in the energy field at present.
Among renewable energy sources, wind energy and solar energy are clean energy sources with the most abundant resources in China and mature power generation technology, however, the problem of wind and light abandoning in remote areas far away from a load center is serious, and in order to solve the problem of wind and light abandoning, new energy sources must be transported to the load center for a long distance. Because wind energy and solar energy have the characteristic of high volatility and strong randomness, the mode of thermal power, wind power and photovoltaic coupling is adopted at present to adapt to peak shaving changes caused by wind energy and solar energy fluctuation. However, in order to ensure the stability of the power grid during wind power, thermal power and photovoltaic coupling, the thermal power unit needs to be used as a peak shaving power supply to finish a peak shaving task for frequent load-changing operation, which has an influence on the safety of the thermal power unit. Therefore, how to evaluate the safety of the thermal power generating unit in the wind power photoelectric thermal power coupling system has very important significance for the large-scale new energy consumption and the research of the outgoing mode in China.
Disclosure of Invention
Aiming at the defects or improvement demands of the prior art, the application provides the method for evaluating the safety of the thermal power generating unit in the wind-light-fire coupling system, and the method can accurately evaluate the safety of the thermal power generating unit in the wind-light-fire coupling system and has very important guiding significance on the movement of the thermal power generating unit.
In order to achieve the above object, according to one aspect of the present application, there is provided a method for evaluating safety of a thermal power generating unit in a wind-solar-fire coupling system, the method comprising: s1: building a wind turbine generator power model based on wind speed and building a photovoltaic turbine generator power model based on environmental parameters; s2: coupling the wind turbine generator power model, the photoelectric turbine generator power model and the thermal power generating unit model to obtain a power tracking system model, and obtaining thermal power generating unit power according to the power tracking system tracking model; s3: obtaining the time-dependent change relation of the temperature at different radiuses of each shaft section of a turbine rotor in the thermal power unit based on the one-dimensional unsteady heat conduction principle of the hollow cylinder without internal heat source according to the thermal power unit power; s4: obtaining the thermal stress of the steam turbine rotor according to the time-dependent change relation of the temperature at different radiuses of each shaft section of the steam turbine rotor and the one-dimensional unstable heat conduction equation, so as to obtain the fatigue loss of the rotor of the thermal power generating unit; s5: carrying out Fourier transformation on output voltage waveforms of an inversion device of a generator of the wind turbine and the photovoltaic turbine respectively to obtain harmonic waves of the wind turbine and the photovoltaic turbine; s6: superposing the harmonic waves of the wind turbine generator and the harmonic waves of the photoelectric turbine generator to act on the shafting of the thermal power generating unit, so that the impact of the harmonic waves on the shafting of the thermal power generating unit can be obtained; s7: and carrying out thermal power unit safety evaluation on impact of fatigue loss and harmonic waves of the thermal power unit rotor on a thermal power unit shafting.
Preferably, step S6 further includes performing equivalent treatment on a shafting of the thermal power generating unit, specifically: and (3) each shaft section of the plurality of section shafting of the thermal power generating unit is equivalent to a concentrated mass block, and the mass blocks are equivalent to spring connection without mass.
Preferably, the shafting equation of the thermal power generating unit is as follows:
wherein Δδ i For angular displacement of rotor on the ith section of shaft, Δω i The angular velocity increment of the rotor on the ith section of shaft; delta T ei For increasing electromagnetic torque of the ith section of shaft, H i Is the inertia constant of the rotor on the ith section of shaft, D ii K is the self-damping coefficient of the rotor on the ith section of shaft i，i+1 ，K i，i-1 Expressed as the elastic coefficient between each adjacent concentrated mass.
Preferably, in step S1, the wind turbine generator set power model P W The method comprises the following steps:
wherein C is the wind energy conversion efficiency coefficient of the blade, ρ is the air density, A is the circular area formed by the air flow when the fan blade of the wind turbine rotates, and v is the wind speed.
Preferably, the photovoltaic unit power model P V The method comprises the following steps:
P V ＝η V SI[1-0.005(t 0 +25)]
wherein eta V For the conversion efficiency of the photovoltaic cell, S is the area of the photovoltaic array, I is the solar irradiation intensity, t 0 Is the temperature.
Preferably, the power tracking system model L (t) is:
L(t)＝P W (t)+P V (t)+P T (t)
wherein P is W (t) is the power of the wind turbine generator set in the period t, P V (t) is the power of the photoelectric unit in the period t, P T (t) is the power of the thermal power generating unit to be calculated at the moment t, L (t) is the preset output power of the load changing along with time at the moment t, and P i (t-1) is the active power of the ith section shaft of the thermal power generating unit in the t-1 period, P i (t) is the active power of the ith section shaft of the thermal power generating unit in the t period,the maximum descending power of the ith section shafting of the thermal power generating unit at a single moment; />The maximum rising power of the ith section shafting of the thermal power generating unit at a single moment.
Preferably, in step S3, the relationship between the temperature T at different radii of each shaft section of the steam turbine rotor and the time τ is:
wherein η=f (P T ，T q )，ηFor the rate of steam temperature rise, P T Is the power of the thermal power generating unit, T q T is the temperature of steam 0 For initial value of rotor, R 0 The outer diameter of the rotor, a is the thermal diffusivity, r is the radius of any point of the rotor, B is the unit node displacement array coefficient, beta is the linear expansion coefficient of the rotor material, n is the number of nodes with temperature values to be calculated, J 0 Initial value for variation calculation in unit, F 0 Is the initial value of the equivalent node force for the concentrated force.
Preferably, the thermal stress σ of the turbine rotor in step S4 th The expression of (2) is:
wherein E is the elastic modulus of the rotor material, v is the Posang ratio of the rotor material, c is the specific heat of the rotor material, and ρ 0 Is the density of the rotor material, lambda is the rotor heat conductivity coefficient, R is the rotor thickness, R=R b -R 0 ，R b Is the inner diameter of the rotor, f is the shape factor, eta g For the g-th steam temperature rise rate, eta g-1 The temperature rise rate of the steam is g-1 th time, K is a time correction factor, and tau g For the time of the g-th steam temperature rise change, τ g-1 The time of the change of the temperature rise of the steam at g-1 time.
Preferably, the electromagnetic torque increment delta T caused by the impact of the harmonic on the shafting of the thermal power generating unit e The method comprises the following steps:
wherein omega 0 The disturbance frequency of the harmonic wave after the superposition of the harmonic wave of the wind turbine generator and the harmonic wave of the photovoltaic turbine generator, E G0 Is the terminal voltage of the thermal power generating unit, U A0 For the initial value delta of bus voltage at grid connection position of wind turbine generator and thermal power generating unit 0 Is the initial value of the voltage phase angle of the machine end of the thermal power generating unit, X G Is the circuit impedance of the thermal power unit, delta is the variation value of the voltage phase angle of the machine end of the thermal power unit, and k p Is the coefficient, k q As the coefficient of the light-emitting diode,X W is the total circuit impedance of the wind power optical unit, E W0 Is the voltage of the fan end and the photovoltaic end, theta 0 And the initial phase angle of the machine end voltage for grid connection of the wind power optical machine set.
Preferably, step S4 obtains fatigue loss of the rotor of the thermal power generating unit by performing finite element analysis on thermal stress of the rotor of the steam turbine.
In general, compared with the prior art, the evaluation method for the safety of the thermal power generating unit in the wind-light-fire coupling system has the following beneficial effects:
1. according to the application, fatigue loss of the rotor of the thermal power unit in the wind-solar-fire coupling system and impact influence of harmonic waves of the wind power unit and the thermal power unit on the rotor rotating shaft can be known through thermal stress analysis, so that safety evaluation of the whole shaft system of the thermal power unit can be realized, and the evaluation is more comprehensive;
2. the coupling power of the thermal power generating unit is obtained by constructing a wind turbine power model and a photovoltaic power model, so that the rotor temperature field and the thermal stress of the rotor are reversely pushed according to the power, and the method is simple and easy to realize;
3. in the shafting analysis process of the thermal power generating unit, the spring equivalent mode is adopted to separate shafting to calculate the influence of harmonic waves on each section of shaft, calculation is more accurate, harmonic wave impact of each shaft end can be obtained, and therefore accurate and efficient guidance is provided for subsequent safety evaluation.
Drawings
FIG. 1 is a step diagram of a method for evaluating the safety of a thermal power generating unit in a wind-solar-electric coupling system;
fig. 2 is a flowchart of a method for evaluating safety of a thermal power generating unit in a wind-solar-electric coupling system.
Detailed Description
The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application. In addition, the technical features of the embodiments of the present application described below may be combined with each other as long as they do not collide with each other.
Referring to fig. 1 and 2, the application provides a method for evaluating safety of a thermal power generating unit in a wind-solar-fire coupling system, which specifically comprises the following steps S1 to S7.
S1: and constructing a wind turbine power model based on the wind speed and constructing the wind turbine power model based on the environmental parameters.
In the field of wind energy prediction, wind speed and wind power have close relation, and a power model P of a wind turbine generator set W The method comprises the following steps:
wherein C is the wind energy conversion efficiency coefficient of the blade, ρ is the air density, A is the circular area formed by the air flow when the fan blade of the wind turbine rotates, and v is the wind speed.
The output power of the photovoltaic power station is affected by various factors, such as solar irradiation intensity, wind speed, relative humidity, temperature, weather and the like, and the power model P of the photovoltaic unit V The method comprises the following steps:
P V ＝η V SI[1-0.005(t 0 +25)]
wherein eta V For the conversion efficiency of the photovoltaic cell, S is the area of the photovoltaic array, I is the solar irradiation intensity, t 0 Is the temperature.
S2: and coupling the wind turbine generator power model, the photoelectric turbine generator power model and the thermal power generating unit model to obtain a power tracking system model, and obtaining the thermal power generating unit power according to the power tracking system tracking model.
The external output process of the wind-solar-electric coupling system meets the energy balance principle and the climbing rate constraint of the thermal power unit, and the power tracking system model L (t) is as follows:
L(t)＝P W (t)+P V (t)+P T (t)
wherein P is W (t) is the power of the wind turbine generator set in the period t, P V (t) is the power of the photoelectric unit in the period t, P T (t) is the power of the thermal power generating unit to be calculated at the moment t, L (t) is the preset output power of the load changing along with time at the moment t, and P i (t-1) is the active power of the ith section shaft of the thermal power generating unit in the t-1 period, P i (t) is the active power of the ith section shaft of the thermal power generating unit in the t period,the maximum descending power of the ith section shafting of the thermal power generating unit at a single moment; />The maximum rising power of the ith section shafting of the thermal power generating unit at a single moment.
S3: and obtaining the time-dependent change relation of the temperature at different radiuses of each shaft section of the turbine rotor in the thermal power unit based on the one-dimensional unsteady heat conduction principle of the hollow cylinder without internal heat source according to the thermal power unit power.
Regarding the steam turbine as an infinite cylinder with a center hole and the initial temperature is uniform, the problem is simplified into a one-dimensional unsteady heat conduction problem of a hollow cylinder without an internal heat source, when the initial temperature of the rotor is in a uniform state and is consistent with the initial steam temperature, if the steam temperature is linearly changed along with the time, the change relation of the temperature T at different radiuses of each shaft section of the rotor of the steam turbine along with the time tau is as follows:
wherein η=f (P T ，T q ) Eta is the steam temperature rise rate, P T Is the power of the thermal power generating unit, T q T is the temperature of steam 0 For initial value of rotor, R 0 Is the outer diameter of the rotor, a is the thermal diffusivity, and r is any one of the rotorsThe radius of the point, B is the displacement array coefficient of the unit node, beta is the expansion coefficient of the rotor material line, n is the number of nodes with temperature values to be calculated, J 0 Initial value for variation calculation in unit, F 0 Is the initial value of the equivalent node force for the concentrated force.
S4: and obtaining the thermal stress of the steam turbine rotor according to the time-dependent change relation of the temperature at different radiuses of each shaft section of the steam turbine rotor and the one-dimensional unstable heat conduction equation, so as to obtain the fatigue loss of the rotor of the thermal power generating unit.
Thermal stress sigma of steam turbine rotor th The expression of (2) is:
wherein E is the elastic modulus of the rotor material, v is the Posang ratio of the rotor material, c is the specific heat of the rotor material, and ρ 0 Is the density of the rotor material, lambda is the rotor heat conductivity coefficient, R is the rotor thickness, R=R b -R 0 ，R b Is the inner diameter of the rotor, f is the shape factor, eta g For the g-th steam temperature rise rate, eta g-1 The temperature rise rate of the steam is g-1 th time, K is a time correction factor, and tau g For the time of the g-th steam temperature rise change, τ g-1 The time of the change of the temperature rise of the steam at g-1 time.
The fatigue loss of the rotor of the thermal power generating unit can be obtained by carrying out finite element analysis on the thermal stress of the rotor of the steam turbine.
S5: and carrying out Fourier transformation on output voltage waveforms of the generator of the wind turbine and the inverter of the photovoltaic unit respectively to obtain harmonic waves of the wind turbine and the photovoltaic unit.
For a wind power grid-connected system, because a high-power conversion state is adopted, power electronic devices in the conversion device are the most important harmonic sources in the wind power device. Here, a fast constant frequency wind power generator is taken as an example. Modern wind power generators all adopt doubly-fed asynchronous generators, and wind power generators are mainly analyzed from stator windings and rotor windings at present. The method comprises the steps that higher harmonic waves generated by a rotor side alternating current excitation system are main harmonic wave sources in grid-connected operation of a wind power system, and output voltage U waveforms of the higher harmonic waves are obtained through Fourier analysis:
wherein U is k For each harmonic voltage maximum, it can be seen that the harmonic frequency is 6n±1 (n=1, 2,3 …), each positive sequence harmonic voltage component is represented when k=6n+1, each negative sequence harmonic voltage component is represented when k=6n-1, and pulse-type change occurs when the direct current side voltage is added, and the change can bring fundamental frequency integer multiple harmonic to the whole system through the inverter.
The harmonic wave generated by the inverter in the photovoltaic power generation system is a main harmonic wave source in the power grid, the current inverter control uses an asynchronous modulation mode, and synchronous modulation can be regarded as a special condition of asynchronous modulation, so that the problem of harmonic wave generation can be analyzed from the asynchronous modulation mode. According to the harmonic characteristic analysis, the Fourier basic expansion of a half bridge can be obtained first, and then the voltage Fourier series harmonic expansion is obtained by using the harmonic superposition principle, so that the characteristics of the Fourier series expansion specific harmonic are as follows in an asynchronous modulation mode:
(1) n=1, 3,5 … …, k=3 (2 m-1), n=1, 2,3
(2) n=2, 4,6 … …, k=6m+1, m=0, 1,2, 3.; k=6 m-1, m=0, 1,2,3
Wherein u is ab For the fundamental component of the line voltage, u d/2 Is a half-voltage wave component of a direct-current capacitor, J k Is Bessel number, omega 0 For angular frequency, omega of signal wave s Is the carrier angular frequency, phi is the primary phaseAnd (5) corners.
S6: and superposing the harmonic waves of the wind turbine generator and the harmonic waves of the photoelectric unit to act on the shafting of the thermal power unit, so that the impact of the harmonic waves on the shafting of the thermal power unit can be obtained.
The step also comprises the step of carrying out equivalent treatment on the shafting of the thermal power generating unit, and specifically comprises the following steps:
and (3) each shaft section of the plurality of section shafting of the thermal power generating unit is equivalent to a concentrated mass block, and the mass blocks are equivalent to spring connection without mass.
The shafting equation of the thermal power generating unit after the equivalence is as follows:
wherein Δδ i For angular displacement of rotor on the ith section of shaft, Δω i The angular velocity increment of the rotor on the ith section of shaft; delta T ei For increasing electromagnetic torque of the ith section of shaft, H i Is the inertia constant of the rotor on the ith section of shaft, D ii K is the self-damping coefficient of the rotor on the ith section of shaft i，i+1 ，K i，i-1 Expressed as the elastic coefficient between each adjacent concentrated mass, and imax is the number of axial segments.
Electromagnetic torque increment delta T caused by impact of harmonic waves on thermal power unit shafting e The method comprises the following steps:
wherein omega 0 The disturbance frequency of the harmonic wave after the superposition of the harmonic wave of the wind turbine generator and the harmonic wave of the photovoltaic turbine generator, E G0 Is the terminal voltage of the thermal power generating unit, U A0 For the initial value delta of bus voltage at grid connection position of wind turbine generator and thermal power generating unit 0 Is the initial value of the voltage phase angle of the machine end of the thermal power generating unit, X G Is the circuit impedance of the thermal power unit, delta is the variation value of the voltage phase angle of the machine end of the thermal power unit, and k p Is the coefficient, k q As the coefficient of the light-emitting diode,X W is the total circuit impedance of the wind power optical unit, E W0 Is the voltage of the fan end and the photovoltaic end, theta 0 And the initial phase angle of the machine end voltage for grid connection of the wind power optical machine set.
S7: and carrying out thermal power unit safety evaluation on impact of fatigue loss and harmonic waves of the thermal power unit rotor on a thermal power unit shafting.
Therefore, management personnel can comprehensively evaluate the safety of the thermal power generating unit by analyzing the thermal stress dangerous part and the harmonic impact dangerous section. The thermal stress fatigue analysis is mainly aimed at the rotor at the inner position of the high and medium pressure cylinder, and the harmonic impact analysis is mainly aimed at the coupling position outside the cylinder.
It will be readily appreciated by those skilled in the art that the foregoing description is merely a preferred embodiment of the application and is not intended to limit the application, but any modifications, equivalents, improvements or alternatives falling within the spirit and principles of the application are intended to be included within the scope of the application.
Claims (9)
1. The method for evaluating the safety of the thermal power generating unit in the wind-solar-fire coupling system is characterized by comprising the following steps of:
s1: building a wind turbine generator power model based on wind speed and building a photovoltaic turbine generator power model based on environmental parameters;
s2: coupling the wind turbine generator power model, the photoelectric turbine generator power model and the thermal power generating unit model to obtain a power tracking system model, and obtaining thermal power generating unit power according to the power tracking system tracking model;
wherein, the power tracking system model L (t) is:
L(t)＝P W (t)+P V (t)+P T (t)
wherein P is W (t) is the power of the wind turbine generator set in the period t, P V (t) is the power of the photoelectric unit in the period t, P T (t) is the power of the thermal power generating unit to be calculated at the moment t, L (t) is the preset output power of the load changing along with time at the moment t, and P i (t-1) is the active power of the ith section shaft of the thermal power generating unit in the t-1 period, P i (t) is the active power of the ith section shaft of the thermal power generating unit in the t period,the maximum descending power of the ith section shafting of the thermal power generating unit at a single moment; />The maximum rising power of the ith section shafting of the thermal power generating unit at a single moment;
s3: obtaining the time-dependent change relation of the temperature at different radiuses of each shaft section of a turbine rotor in the thermal power unit based on the one-dimensional unsteady heat conduction principle of the hollow cylinder without internal heat source according to the thermal power unit power;
s4: obtaining the thermal stress of the steam turbine rotor according to the time-dependent change relation of the temperature at different radiuses of each shaft section of the steam turbine rotor and the one-dimensional unstable heat conduction equation, so as to obtain the fatigue loss of the rotor of the thermal power generating unit;
s5: carrying out Fourier transformation on output voltage waveforms of an inversion device of a generator of the wind turbine and the photovoltaic turbine respectively to obtain harmonic waves of the wind turbine and the photovoltaic turbine;
s6: superposing the harmonic waves of the wind turbine generator and the harmonic waves of the photoelectric turbine generator to act on the shafting of the thermal power generating unit, so that the impact of the harmonic waves on the shafting of the thermal power generating unit can be obtained;
s7: and carrying out thermal power unit safety evaluation on impact of fatigue loss and harmonic waves of the thermal power unit rotor on a thermal power unit shafting.
2. The method according to claim 1, wherein step S6 further comprises performing equivalent treatment on a shaft system of the thermal power generating unit, specifically:
and (3) each shaft section of the plurality of section shafting of the thermal power generating unit is equivalent to a concentrated mass block, and the mass blocks are equivalent to spring connection without mass.
3. The method of claim 2, wherein the shafting equation of the thermal power plant is:
wherein Δδ i For angular displacement of rotor on the ith section of shaft, Δω i The angular velocity increment of the rotor on the ith section of shaft; delta T ei For increasing electromagnetic torque of the ith section of shaft, H i Is the inertia constant of the rotor on the ith section of shaft, D ii K is the self-damping coefficient of the rotor on the ith section of shaft i,i+1 ，K i,i-1 Expressed as the elastic coefficient between each adjacent concentrated mass.
4. The method of claim 1, wherein the stroke motor group power model P is in step S1 W The method comprises the following steps:
wherein C is the wind energy conversion efficiency coefficient of the blade, ρ is the air density, A is the circular area formed by the air flow when the fan blade of the wind turbine rotates, and v is the wind speed.
5. The method according to claim 1, wherein the photovoltaic unit power model P V The method comprises the following steps:
P V ＝η V SI[1-0.005(t 0 +25)]
wherein eta V For the conversion efficiency of the photovoltaic cell, S is the area of the photovoltaic array, I is the solar irradiation intensity, t 0 Is the temperature.
6. The method according to claim 1, wherein in step S3, the temperature T at different radii of each shaft section of the steam turbine rotor is related to time τ by:
wherein η=f (P T ,T q ) Eta is the steam temperature rise rate, P T Is the power of the thermal power generating unit, T q T is the temperature of steam 0 For initial value of rotor, R 0 The outer diameter of the rotor, a is the thermal diffusivity, r is the radius of any point of the rotor, B is the unit node displacement array coefficient, beta is the linear expansion coefficient of the rotor material, n is the number of nodes with temperature values to be calculated, J 0 Initial value for variation calculation in unit, F 0 Is the initial value of the equivalent node force for the concentrated force.
7. The method according to claim 6, wherein the thermal stress σ of the turbine rotor in step S4 th The expression of (2) is:
wherein E is the elastic modulus of the rotor material, v is the Posang ratio of the rotor material, c is the specific heat of the rotor material, and ρ 0 Is the density of the rotor material, lambda is the rotor heat conductivity coefficient, R is the rotor thickness, R=R b －R 0 ，R b Is the inner diameter of the rotor, f is the shape factor, eta g For the g-th steam temperature rise rate, eta g-1 The temperature rise rate of the steam is g-1 th time, K is a time correction factor, and tau g For the time of the g-th steam temperature rise change, τ g-1 The time of the change of the temperature rise of the steam at g-1 time.
8. The method of claim 1, wherein the harmonic produces an electromagnetic torque delta Δt from an impact on a thermal power plant shafting e The method comprises the following steps:
wherein omega 0 The disturbance frequency of the harmonic wave after the superposition of the harmonic wave of the wind turbine generator and the harmonic wave of the photovoltaic turbine generator, E G0 Is the terminal voltage of the thermal power generating unit, U A0 For the initial value delta of bus voltage at grid connection position of wind turbine generator and thermal power generating unit 0 Is the initial value of the voltage phase angle of the machine end of the thermal power generating unit, X G Is the circuit impedance of the thermal power unit, delta is the voltage phase angle change value of the machine end of the thermal power unit, and k p Is the coefficient, k q As the coefficient of the light-emitting diode,X W is the total circuit impedance of the wind power optical unit, E W0 Is the voltage of the fan end and the photovoltaic end, theta 0 And the initial phase angle of the machine end voltage for grid connection of the wind power optical machine set.
9. The method according to claim 1, wherein step S4 obtains fatigue loss of the rotor of the thermal power generating unit by performing finite element analysis on thermal stress of the rotor of the steam turbine.
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