CN116826736A - Flexible resource allocation method and system with inertia constraints for high-proportion new energy systems - Google Patents
Flexible resource allocation method and system with inertia constraints for high-proportion new energy systems Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for AC mains or AC distribution networks
- H02J3/002—Flicker reduction, e.g. compensation of flicker introduced by non-linear load
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- H02J3/0014—
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for AC mains or AC distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for AC mains or AC distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
- H02J3/466—Scheduling the operation of the generators, e.g. connecting or disconnecting generators to meet a given demand
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Abstract
The invention provides a flexible resource allocation method and a system for high-proportion new energy system inertia constraint, and relates to the technical field of new energy, wherein the method comprises the following steps: acquiring flexibility requirements of a load-based and intermittent new energy power generation computing system under different time scales; acquiring actual running state data of a high-proportion new energy system, dynamically calculating the inertia and the minimum inertia limit value of the system according to the actual running state data, and taking the minimum inertia limit value as a constraint index of flexible resource allocation of the high-proportion new energy system; obtaining flexible resources capable of providing flexible technology for a high-proportion new energy system; and carrying out joint optimization on the flexible resources under the condition of considering the flexible requirements, wherein the optimization meets constraint indexes of flexible resource allocation of a high-proportion new energy system. The method solves the problems of constraint calculation of system inertia and allocation of various flexible resources in a future high-proportion new energy power system.
Description
Technical Field
The present document relates to the technical field of new energy, and in particular, to a method and a system for configuring flexible resources with high-proportion new energy system inertia constraint.
Background
The magnitude of the inertia of the power system reflects the capability of the system to maintain the frequency change of the system after the power change, and the larger system inertia is beneficial to maintaining the frequency stability of the system. Most of the generators in the traditional system are synchronous generators and are the most main sources for providing traditional inertia, so that the larger the capacity of the system is, the larger the inertia of the system is in general; for the power grid accessed by large-scale new energy, a large number of power generation equipment are connected with the power grid through a frequency converter, and if special control measures are not adopted, inertia is not provided for the system, and the situation that the system capacity is relatively large but the inertia is not large can occur. The large-scale development of new energy power generation such as wind power, photovoltaic and the like reduces the power generation capacity ratio of the synchronous generator in a power grid, so that the inertia level of the system is reduced, and huge pressure is brought to the frequency voltage stability of a power system.
In order to alleviate the system operation problem caused by the reduction of the operation inertia due to the high-proportion new energy access, the related research adopts a virtual inertia control method, namely, the inertia of a synchronous generator can be replaced by the new energy, energy storage or direct current power transmission through specific equipment and improved control technology, so as to meet the requirement of system regulation. With the increase of the new energy duty ratio and the decrease of the system inertia level, the new energy power generation system adopting virtual inertia control provides additional virtual inertia for the power grid to help the power grid to safely and stably run, so that quantitative evaluation analysis is necessary for the system inertia of the power grid under the condition that the new energy access proportion is gradually increased.
Disclosure of Invention
The invention provides a flexible resource allocation method and a system for high-proportion new energy system inertia constraint, which are used for solving the problems of system inertia constraint calculation and various flexible resource allocation in a future high-proportion new energy power system.
The invention provides a flexible resource allocation method of high-proportion new energy system inertia constraint, which comprises the following steps:
s1, acquiring flexibility requirements of a load and intermittent new energy power generation computing system under different time scales;
s2, acquiring actual running state data of the high-proportion new energy system, dynamically calculating inertia and a minimum inertia limit value of the system according to the actual running state data, and taking the minimum inertia limit value as a constraint index of flexible resource allocation of the high-proportion new energy system;
s3, obtaining flexible resources which can provide flexible technology for a high-proportion new energy system from the angles of a power supply, a power grid, a load and energy storage;
and S4, carrying out joint optimization on the flexible resources under the condition of considering the flexible requirements, and optimizing constraint indexes of flexible resource allocation of the high-proportion new energy system.
The invention provides a flexible resource allocation system of high-proportion new energy system inertia constraint, which comprises:
the flexibility demand module is used for acquiring flexibility demands of the load-based and intermittent new energy power generation computing system under different time scales;
the constraint index module is used for acquiring actual running state data of the high-proportion new energy system, dynamically calculating the inertia and the minimum inertia limit value of the system according to the actual running state data, and taking the minimum inertia limit value as a constraint index of flexible resource allocation of the high-proportion new energy system;
the flexible resource module is used for acquiring flexible resources which can provide flexible technology for the high-proportion new energy system from the angles of power supply, power grid, load and energy storage;
and the joint optimization module is used for carrying out joint optimization on the flexible resources under the condition of considering the flexible requirements, and the joint optimization meets constraint indexes of flexible resource allocation of the high-proportion new energy system.
In the embodiment of the invention, the lowest inertia of the system is used as a constraint condition, when the inertia of the system is lower than the lowest limit value, the flexibility resource is adjusted, and the inertia of the system is increased by increasing the output of the synchronous generator type unit, so that the constraint condition of the inertia is met. The system inertia constraint index and the application method thereof in the flexibility analysis process are beneficial to better considering the influence of the system frequency characteristic in the resource configuration.
Drawings
For a clearer description of one or more embodiments of the present description or of the solutions of the prior art, the drawings that are necessary for the description of the embodiments or of the prior art will be briefly described, it being apparent that the drawings in the description that follow are only some of the embodiments described in the description, from which, for a person skilled in the art, other drawings can be obtained without inventive faculty.
FIG. 1 is a flow chart of a method for configuring flexible resources with high-proportion new energy system inertia constraint according to an embodiment of the invention;
FIG. 2 is a schematic diagram of a flexible resource allocation system with high-proportion new energy system inertia constraint according to an embodiment of the present invention;
FIG. 3 is a schematic view of day flexibility of an embodiment of the present invention;
FIG. 4 is a schematic illustration of the flexibility of an embodiment of the present invention;
FIG. 5 is a schematic diagram of a basic process for analyzing system flexibility according to an embodiment of the present invention;
fig. 6 is a schematic diagram of 11 partitions of an interconnected grid according to an embodiment of the present invention;
FIG. 7 is a diagram of the payload of partitions 4 and 8 according to an embodiment of the invention;
FIG. 8 is a diagram illustrating the flexibility requirements of the respective partition payloads according to an embodiment of the present invention;
FIG. 9 is a diagram of the inertia and minimum inertia limits of the partition 8 according to an embodiment of the present invention;
FIG. 10 is a schematic diagram of power generation and tie-line power for a segment 8 for a series of 4 days in accordance with an embodiment of the present invention;
FIG. 11 is a schematic diagram of the inertia and minimum inertia of a partition 8 for a continuous 4 days according to an embodiment of the present invention;
FIG. 12 is a schematic diagram of power generation after 4 consecutive days of inertia consideration for partition 8 according to an embodiment of the present invention.
Detailed Description
In order to enable a person skilled in the art to better understand the technical solutions in one or more embodiments of the present specification, the technical solutions in one or more embodiments of the present specification will be clearly and completely described below with reference to the drawings in one or more embodiments of the present specification, and it is obvious that the described embodiments are only some embodiments of the present specification, not all embodiments. All other embodiments, which can be made by one or more embodiments of the present disclosure without inventive faculty, are intended to be within the scope of the present disclosure.
Method embodiment
According to an embodiment of the present invention, a method for configuring flexible resources of high-proportion new energy system inertia constraint is provided, fig. 1 is a flowchart of a method for configuring flexible resources of high-proportion new energy system inertia constraint according to an embodiment of the present invention, and according to fig. 1, a method for configuring flexible resources of high-proportion new energy system inertia constraint according to an embodiment of the present invention specifically includes:
s1, acquiring flexibility requirements of a load and intermittent new energy power generation computing system under different time scales;
according to the embodiment of the invention, the evaluation index of the flexibility requirement is provided by considering the flexibility requirement of different time scales such as day, week and year, wherein the evaluation index comprises day flexibility, week flexibility and year flexibility, and the evaluation of the flexibility requirement of different time scales is realized. The flexibility index is usually based on the net load, which reflects the comprehensive change process of the system load and new energy sources such as wind power, photovoltaic and the like. For changes in the payload, the characteristics exhibited by different time scales and the corresponding primary influencing factors are different. The fluctuation in the hour is mainly influenced by the random fluctuation of intermittent new energy; fluctuation in one day is mainly influenced by a load curve and photovoltaic power generation; the fluctuation in one week is mainly influenced by the load change of working days and rest days and the periodic fluctuation of wind power; fluctuations within one year are mainly affected by seasonal changes in load, solar energy, wind power.
FIG. 3 is a schematic diagram of daily flexibility, which is the difference between the daily payload of each hour in a day and the average of the daily payloads, according to an embodiment of the present invention, and the daily flexibility index reflects the fluctuation degree of the daily payloads, as shown in FIG. 3. The day flexibility of all days of the year adds up to the day flexibility of the year.
FIG. 4 is a schematic diagram of week flexibility, which is the difference between the average of the daily payloads of the week and the average of the week payloads, as shown in FIG. 4, and the week flexibility index reflects the fluctuation degree of the payloads in the week. The addition of weekly flexibility for all weeks of a year is the weekly flexibility requirement required for a year.
Annual flexibility is the difference between the average of the payloads per month in a year and the average of the payloads in a year. The three flexibility indexes corresponding to different time scales reflect the demand degree of the flexibility resource on one hand and reflect the requirement of the flexibility resource characteristic on the other hand.
S2, acquiring actual running state data of the high-proportion new energy system, dynamically calculating inertia and a minimum inertia limit value of the system according to the actual running state data, and taking the minimum inertia limit value as a constraint index of flexible resource allocation of the high-proportion new energy system; the S2 of the embodiment of the invention specifically comprises the following steps:
s21: acquiring time sequence production data of the regional power grid in a preset time range, wherein the time sequence production data comprise power grid data and power generation data, the power grid data comprise grid topology, node load, total system load, maximum frequency change rate limit and maximum power shortage, and the power generation data comprise installed capacity, real-time power generation power, generator rotational kinetic energy and virtual inertia constants of each synchronous generator and each new energy station;
s22: and (3) calculating the total capacity of the synchronous generator in the starting state and the new energy station in the grid-connected power generation state in the regional power grid according to the following formula by using the installed capacity of each synchronous generator and each new energy station obtained in the step (S21):
wherein:
S sys the total capacity of all the synchronous generators started up and all the new energy stations for grid-connected power generation in the regional power grid is in megawatts; s is S Gen,i The unit is megawatt for the installed capacity of the synchronous generator i; s is S Re,k The unit is megawatt for the installed capacity of the new energy station k; x is x i The synchronous generator i is in an on-off state (when the synchronous generator i is equal to 0, the synchronous generator i is powered off, and when the synchronous generator i is equal to 1, the synchronous generator i is powered on); x is x k The power generation state is the grid-connected power generation state of the new energy station k (no power generation is generated when the power generation state is stopped when the power generation state is equal to 0, and the power generation state is grid-connected when the power generation state is equal to 1); n (N) Gen The total number of synchronous generators in the regional power grid; n (N) Re The total number of new energy stations in the regional power grid;
s23: and obtaining inertia constants of each unit of each type in the network according to the following formula by using the rotation kinetic energy and the installed capacity of the generator of each synchronous generator:
wherein:
H i the inertia constant of the synchronous generator i (comprising a generator and a water turbine or a steam turbine) is expressed in seconds; e (E) MWS,i The unit is megawatt-second which is the generator kinetic energy of the synchronous generator i;
s24: in actual operation, the operation inertia of the system can dynamically change along with the change of the operation state of the power grid, and when the real-time power generation power of new energy stations such as wind power, photovoltaic and the like is higher, the traditional synchronous generator set such as thermal power and the like can be partially stopped, and the actual operation inertia of the system can be lower. Considering a real-time start-stop mode of the system, the total running inertia level of the system of the regional power grid at a certain running moment can be calculated by summation according to the rotational kinetic energy of all the synchronous generators which are started in the system:
wherein: i sys The total inertia level of the system at the running time is expressed in megawatts-seconds;
s25: the total system running inertia constant of the regional power grid at a certain running time can be calculated by the inertia constant of the synchronous generator in a starting state and the installed capacity of the synchronous generator:
wherein: h op The real-time running inertia constant of the system is given in seconds;
s26: considering that part of new energy stations adopt virtual inertia control, the system running inertia constant of the regional power grid at a certain running time is obtained by synthesizing the rotational inertia of a traditional synchronous generator and the virtual inertia of the new energy stations:
wherein:
H VI the real-time running inertia constant of the system taking the virtual inertia of the new energy into consideration is expressed in seconds; h k The virtual inertia constant of the new energy station k is given in seconds;
s27: the frequency change of the regional power system at a certain running time is directly related to the running inertia and unbalanced power of the system, and the larger the system inertia is, the smaller the frequency change corresponding to the same power change is, so that the frequency change rate of the system can be written as:
wherein: df/dt is the rate of change of the system frequency in hertz/second; Δp is the amount of power change in megawatts when a disturbance occurs to the system;f N is the rated frequency of the system, and is expressed in hertz, usually 50 hertz;
taking into account the maximum frequency change rate limit and the maximum power change amount in the system, calculating the minimum inertia constant limit of the system according to the following formula:
wherein: h min The minimum inertia constant limit value of the system is expressed in seconds; ΔP max The maximum power variation which can occur when the system is disturbed is expressed in megawatts; df (df) max The dt is the maximum frequency change rate allowed by the regional power grid, and the unit is hertz/second;
s3, obtaining flexible resources which can provide flexible technology for a high-proportion new energy system from the angles of a power supply, a power grid, a load and energy storage; s3 specifically comprises:
the power supply side comprises all traditional power plants, such as coal-fired units, hydroelectric units, gas units and the like, and the demand for the gas units is gradually increased along with the increase of the new energy proportion. In addition, the method also comprises the adjustment of uncontrollable power sources such as wind power, photovoltaic and the like, such as wind curtailment, light curtailment and the like;
the power grid side can fully utilize the power regulation capability of the interconnection line, realize complementation among different areas and realize the absorption of intermittent renewable energy sources in a larger range;
the load side may utilize a new type of load with a certain response capability. For example, an electric vehicle may be utilized to achieve orderly charging, with a set of loads having a demand side response capability to achieve load regulation;
the energy storage is an important component of flexible resources, and comprises various types of pumped storage, electrochemical energy storage and the like, the response time can be from seconds, minutes to several hours, and the energy storage with different response characteristics can meet different flexibility requirements;
flexibility analysis requires consideration of locally available flexibility resources. The availability of flexible resources is related to the actual resource situation of the area under investigation. It is also necessary to consider the flexible resource situation in the vicinity and the potential for resource complementation via the tie-lines. The different forms of flexible resources need to be analyzed in consideration of relevant technical and economic parameters such as investment costs, running costs, technical constraints, etc.
S4, carrying out joint optimization on the flexible resources under the condition of considering the flexible requirements, and optimizing constraint indexes of flexible resource allocation of the high-proportion new energy system; s4 specifically comprises the following steps:
the optimization analysis of the system flexibility resources is an optimization process performed on the basis of the available resources determined in the step S3, the technology and the economic parameters thereof, and inertia constraint indexes proposed in the step S2 are required to be considered to meet the flexibility requirement indexes calculated in the step S1.
The objective function of the optimization analysis may be to minimize investment or/and operating costs. The objective functions may all vary due to the individual characteristics and specific requirements of the actual system. In the joint optimization process, optimization needs to be performed based on a data sequence of a period of time, and the influence of adjacent areas is considered. Because different weather conditions can have a great influence on the output and the load of the intermittent new energy, different scenes corresponding to different weather conditions need to be considered in actual optimization.
Taking an interconnected power grid comprising 11 partitions as an example, the method for configuring the flexible resources with the constraint of the high-proportion new energy system inertia in the embodiment of the invention is specifically described, the basic process of analyzing the system flexibility shown in fig. 5 is analyzed, the requirement condition of the flexible resources and the constraint condition of the inertia are needed to be known first, then the available flexible resources are analyzed, finally the comprehensive optimization of the flexible resources is performed, the influence of different types of flexible resources on the flexible requirements can be obtained according to the optimization result, the basis is provided for the operation scheduling and the optimization configuration of the flexible resources, and the method comprises the following steps:
fig. 6 is a schematic diagram of 11 partitions of an interconnected power grid in a specific implementation manner of the embodiment of the invention, where the power generation resources of the whole system mainly include traditional power sources such as coal power, nuclear power, gas power generation, hydroelectric power and the like and intermittent renewable energy sources such as wind power, photovoltaic and the like. Firstly, calculating a flexibility demand index, equivalent inertia and a lowest constraint index of a system, then selecting coal power, nuclear power, gas power generation, hydropower and a connecting line as flexibility adjustment resources, and finally using the lowest operation cost as an objective function to maximally utilize new energy and carry out operation optimization analysis. The result can give flexibility demands of different time scales and contribution degrees of different flexibility resources, and provide parameters for the configuration of the flexibility resources.
According to the steps shown in fig. 5, the flexibility requirements of the system are first calculated:
and subtracting the wind power and photovoltaic output from the load of each region to obtain the net load. Due to the large wind and photovoltaic capacities, the volatility of the net load is substantially increased, and the net loads of partitions 4 and 8 are even negative at some moments in time, as shown in fig. 7.
The daily flexibility, weekly flexibility and annual flexibility indexes can be calculated based on the payload, and the results of different partitions are shown in fig. 8, and because the main factors influencing the flexibility of each partition are different, certain differences exist in the corresponding daily, weekly and annual flexibility demands, and the factors are related to the load characteristics, the duty ratio and distribution of wind power and photovoltaics, the seasonal characteristics and the like.
Computing inertia constraints of a system:
the system inertia is related to the running state, and changes with the running state, and the system inertia at each moment can be calculated according to S26, and the minimum inertia limit of the system is calculated according to S27. Since the partition model adopted in this example does not contain detailed information of a specific generator set, it can only be calculated according to different power generation types by using a given inertia time constant, and typical inertia constants adopted in the european power grid planning data are adopted herein, as shown in table 1 in particular:
TABLE 1 typical inertia constant Meter
Taking partition 8 as an example, assuming a maximum power change of 1 000MW and a maximum frequency change of 0.5Hz/s, the calculated system inertia and minimum inertia limit are shown in FIG. 9 based on the optimization results without considering the inertia constraint.
Optimization analysis of system operation
In the optimization analysis process of the system, the considered flexible resources comprise coal electricity, nuclear power, gas power generation, hydropower and connecting lines, and the lowest cost is used as an objective function to perform optimization calculation. Costs may include investment costs, operating costs, fuel costs, carbon dioxide costs, and the like. For simplicity, this example only considers marginal costs (mainly fuel costs and carbon dioxide costs). The marginal costs for the different resources are shown in table 2:
TABLE 2 schematic of marginal cost for different resource utilization
The whole interconnection system arranges the generator output in an economically optimal way without considering the inertia effect, and considers the power limit of the interconnection line. The flexibility requirement of each partition is borne by the power generation resources of the area on one hand and the power generation resources of the adjacent partition on the other hand through the connecting lines.
Taking partition 8 as an example, a certain period of 4 consecutive days of power generation and tie line power is shown in fig. 10. As can be seen from fig. 10, the photovoltaic occupancy is relatively high, and in addition to the peak load requirement, the photovoltaic occupancy is output through the connecting lines in the daytime, and when the peak load is carried out at night, a part of hydropower, coal power and the like needs to be increased, and a part of electric quantity is input through the connecting lines. The system inertia has a direct relation with the actual starting-up condition and is dynamically changed.
The system inertia and minimum inertia limits for the 4 day partition 8 are shown in FIG. 11. As can be seen from fig. 11, the moment of maximum photovoltaic power generation power in the daytime has the lowest inertia, and the moment of peak load at night increases the generation of partial thermal power and gas, and the moment of maximum inertia. When Bai Tianguang volt output is maximum, the traditional generator set only has water and electricity, and the proportion of the traditional generator set to the total generated energy is lower than 40%. Therefore, the inertia is reduced more than in the case of the conventional unit power supply. In addition, in part of time periods, the inertia of the system is lower than the minimum limit value, if the constraint of the inertia is considered, the generated energy of the traditional units such as hydropower, thermal power and the like needs to be improved, and redundant wind power and photovoltaic can be conveyed outwards through a connecting wire or discarded.
The unit power generation situation after inertia constraint is considered is shown in fig. 12. As can be seen from fig. 12, the partial hydro-generator set output is increased at the moment when the photovoltaic power is higher, taking into account the minimum inertia limit. If the system inertia is lower than the lowest inertia, the power generation of different types of flexible resources can be greatly influenced.
In order to alleviate the system operation problem caused by the reduction of the operation inertia due to the high-proportion new energy access, the related research adopts a virtual inertia control method, namely, the inertia of a synchronous generator can be replaced by the new energy, energy storage or direct current power transmission through specific equipment and improved control technology, so as to meet the requirement of system regulation. The virtual inertia adds the same electromagnetic and mechanical equations as the traditional synchronous generator into the control strategy of the photovoltaic and wind power generation system, so that the output characteristics similar to the traditional synchronous generator are realized, and the new energy power generation can also provide inertia support for the system. With the increase of the new energy duty ratio and the decrease of the system inertia level, the new energy power generation system adopting virtual inertia control provides additional virtual inertia for the power grid, and helps the power grid to run safely and stably. With the reduction of the inertia of the system, the frequency change rate after disturbance of the system is increased, and when the inertia of the system is smaller than the minimum inertia limit value, the frequency fluctuation is larger than the maximum frequency change rate limit, so that the system is endangered to collapse. Since short-term power imbalance affects the frequency of the system, the inertia of the system is a key factor affecting the frequency variation of the system, reflecting the physical constraints of the power system. When the new energy is high, the inertia of the system may be low, and the frequency characteristic of the system is affected. The system inertia is related to the running state of the system, so that constraint needs to be formed by calculating the running inertia of the system and the minimum inertia limit value of the system at each moment, and the system inertia is used as constraint condition in the aspect of flexible resource allocation of the system, thereby helping the power grid reasonably carry out installation scheme planning and starting-up mode arrangement of various flexible resources.
By adopting the embodiment of the invention, the method has the following beneficial effects:
in the process of optimizing the flexible resources, the lowest inertia of the system is used as a constraint condition, and when the inertia of the system is lower than the lowest limit value, the flexible resources are adjusted, so that the output of the synchronous generator type unit can be possibly increased, the inertia of the system is increased, and the constraint condition of the inertia is met. The system inertia constraint index and the application method thereof in the flexibility analysis process are beneficial to better considering the influence of the system frequency characteristic in the resource configuration.
System embodiment
According to an embodiment of the present invention, there is provided a high-ratio new energy system inertia constraint flexible resource allocation system, and fig. 2 is a schematic diagram of the high-ratio new energy system inertia constraint flexible resource allocation system according to the embodiment of the present invention, and according to fig. 2, the high-ratio new energy system inertia constraint flexible resource allocation system according to the embodiment of the present invention specifically includes:
a flexibility requirement module 20, configured to obtain flexibility requirements of the load-based and intermittent new energy generating computing system under different time scales;
the constraint index module 22 is configured to obtain actual running state data of the high-proportion new energy system, dynamically calculate an inertia and a minimum inertia limit value of the system according to the actual running state data, and use the minimum inertia limit value as a constraint index of flexible resource allocation of the high-proportion new energy system;
a flexible resource module 24, configured to obtain flexible resources from a power source, a power grid, a load, and an energy storage perspective, where the flexible resources can provide a flexible technology for the high-proportion new energy system;
and the joint optimization module 26 is configured to perform joint optimization on the flexible resources under the condition of considering the flexibility requirement, where the joint optimization meets constraint indexes of flexible resource configuration of the high-proportion new energy system.
The flexibility requirement module 20 is specifically configured to:
acquiring a difference value between the daily payload of each hour and the daily payload average value as a daily flexibility requirement;
obtaining a difference value between a daily net load average value in a week and a week net load average value as a week flexibility requirement;
the difference between the average of the payloads per month of the year and the average of the payloads of the year is obtained as the annual flexibility requirement.
The constraint index module 22 obtains actual running state data of the high-proportion new energy system specifically including:
acquiring time sequence production data of the regional power grid in a preset time range, wherein the time sequence production data comprises the following steps: grid data and power generation data; the grid data includes: grid topology, node load, system total load, maximum frequency rate of change limit, and maximum power absence, the power generation data comprising: the installed capacity of each synchronous generator and each new energy station, the real-time generation power, the rotational kinetic energy of the generator and the virtual inertia constant.
The constraint index module 22 dynamically calculates the inertia and the minimum inertia limit of the system according to the actual running state data specifically includes:
acquiring the total capacity of the synchronous generators in the starting state and the new energy stations in the grid-connected power generation state in the regional power grid through a formula 1 according to the installed capacity of each synchronous generator and each new energy station;
wherein S is sys The total capacity of all the synchronous generators started up and all the new energy stations for grid-connected power generation in the regional power grid is in megawatts; s is S Gen,i The unit is megawatt for the installed capacity of the synchronous generator i; s is S Re,k Is the installed capacity of the new energy station k, unitIs megawatt; x is x i For the on-off state of synchronous generator i, x i When the power is equal to 0, the power is turned off, and when the power is equal to 1, the power is turned on; x is x k Is in a grid-connected power generation state of a new energy station k, x k When the power is equal to 0, the power is not generated when the power is stopped, and when the power is equal to 1, the power is generated when the power is connected with the grid; n (N) Gen The total number of synchronous generators in the regional power grid; n (N) Re The total number of new energy stations in the regional power grid;
according to the generator rotation kinetic energy and the installed capacity of each synchronous generator, the inertia constant of each unit of each type in the network is obtained through a formula 2:
wherein: h i The inertia constant of the synchronous generator i is expressed in seconds; e (E) MWSi The unit is megawatt-second which is the generator kinetic energy of the synchronous generator i; the synchronous generator comprises a generator and a water turbine or a steam turbine;
according to the rotational kinetic energy of all the started synchronous generators in the system, the total system running inertia level of the regional power grid at a certain running time is obtained through a formula 3:
wherein: i sys The total inertia level of the system at the running time is expressed in megawatts-seconds;
calculating the total running inertia constant of the system of the regional power grid at a certain running time according to the inertia constant of the synchronous generator in the starting state and the installed capacity of the synchronous generator by the formula 4:
wherein: h op The real-time running inertia constant of the system is given in seconds;
according to the rotational inertia of the traditional synchronous generator and the virtual inertia of the new energy station, the system operation inertia constant of the regional power grid at a certain operation time is obtained through a formula 5:
wherein: h VI The real-time running inertia constant of the system taking the virtual inertia of the new energy into consideration is expressed in seconds; h k The virtual inertia constant of the new energy station k is given in seconds;
obtaining the frequency change rate of the system through a formula 6:
wherein: df/dt is the rate of change of the system frequency in hertz/second; Δp is the amount of power change in megawatts when a disturbance occurs to the system; f (f) N Is the rated frequency of the system, and is expressed in hertz, usually 50 hertz; taking into account the maximum frequency change rate limit and the maximum power change amount in the system;
the minimum inertia constant limit of the system is calculated according to equation 7:
wherein: h min The minimum inertia constant limit value of the system is expressed in seconds; ΔP max The maximum power variation which can occur when the system is disturbed is expressed in megawatts; df (df) max And/dt is the maximum rate of change of frequency allowed by the regional power grid, and is expressed in hertz/second.
The flexible resource module 26 is specifically configured to:
when the flexibility resources are acquired, the flexibility resources of the area and the flexibility resources of the adjacent areas are considered, the potential of resource complementation through the connecting lines is considered, and the related technical and economic parameters are considered when the flexibility resources in different forms are analyzed.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.
Claims (10)
1. A flexible resource allocation method of high-proportion new energy system inertia constraint comprises the following steps:
s1, acquiring flexibility requirements of a load and intermittent new energy power generation computing system under different time scales;
s2, acquiring actual running state data of a high-proportion new energy system, dynamically calculating inertia and a minimum inertia limit value of the system according to the actual running state data, and taking the minimum inertia limit value as a constraint index of flexible resource allocation of the high-proportion new energy system;
s3, obtaining flexible resources which can provide flexible technology for a high-proportion new energy system from the angles of a power supply, a power grid, a load and energy storage;
s4, carrying out joint optimization on the flexible resources under the condition of considering the flexible requirements, wherein the joint optimization meets constraint indexes of flexible resource allocation of the high-proportion new energy system.
2. The method according to claim 1, wherein S1 specifically comprises:
s11, obtaining a difference value between the daily payload of each hour in a day and the average value of the daily payload as a daily flexibility requirement;
s12, obtaining a difference value between a daily net load average value in a week and a week net load average value as a week flexibility requirement;
s13, obtaining the difference value between the average value of the net load of each month in one year and the average value of the net load in one year as the annual flexibility requirement.
3. The method according to claim 1, wherein the step of obtaining actual operation state data of the high-proportion new energy system in S2 specifically includes:
acquiring time sequence production data of the regional power grid in a preset time range, wherein the time sequence production data comprises the following steps: grid data and power generation data; the grid data includes: grid topology, node load, system total load, maximum frequency rate of change limit, and maximum power absence, the power generation data comprising: the installed capacity of each synchronous generator and each new energy station, the real-time generation power, the rotational kinetic energy of the generator and the virtual inertia constant.
4. A method according to claim 3, wherein the dynamically calculating the inertia and minimum inertia limits of the system according to the actual operating state data in S2 comprises:
acquiring the total capacity of the synchronous generators in the starting state and the new energy stations in the grid-connected power generation state in the regional power grid through a formula 1 according to the installed capacity of each synchronous generator and each new energy station;
wherein S is sys The total capacity of all the synchronous generators started up and all the new energy stations for grid-connected power generation in the regional power grid is in megawatts; s is S Gen,i The unit is megawatt for the installed capacity of the synchronous generator i; s is S Re,k The unit is megawatt for the installed capacity of the new energy station k; x is x i For the on-off state of synchronous generator i, x i When the power is equal to 0, the power is turned off, and when the power is equal to 1, the power is turned on; x is x k Is in a grid-connected power generation state of a new energy station k, x k When the power is equal to 0, the power is not generated when the power is stopped, and when the power is equal to 1, the power is generated when the power is connected with the grid; n (N) Gen The total number of synchronous generators in the regional power grid; n (N) Re The total number of new energy stations in the regional power grid;
according to the generator rotation kinetic energy and the installed capacity of each synchronous generator, the inertia constant of each unit of each type in the network is obtained through a formula 2:
wherein: h i The inertia constant of the synchronous generator i is expressed in seconds; e (E) MWS,i The unit is megawatt-second which is the generator kinetic energy of the synchronous generator i; the synchronous generator comprises a generator and a water turbine or a steam turbine;
according to the rotational kinetic energy of all the started synchronous generators in the system, the total system running inertia level of the regional power grid at a certain running time is obtained through a formula 3:
wherein: i sys The total inertia level of the system at the running time is expressed in megawatts-seconds;
calculating the total running inertia constant of the system of the regional power grid at a certain running time according to the inertia constant of the synchronous generator in the starting state and the installed capacity of the synchronous generator by the formula 4:
wherein: h op The real-time running inertia constant of the system is given in seconds;
according to the rotational inertia of the traditional synchronous generator and the virtual inertia of the new energy station, the system operation inertia constant of the regional power grid at a certain operation time is obtained through a formula 5:
wherein: h VI The real-time running inertia constant of the system taking the virtual inertia of the new energy into consideration is expressed in seconds; h k The virtual inertia constant of the new energy station k is given in seconds;
obtaining the frequency change rate of the system through a formula 6:
wherein: df/dt is the rate of change of the system frequency in hertz/second; Δp is the amount of power change in megawatts when a disturbance occurs to the system; f (f) N Is the rated frequency of the system, and is expressed in hertz, usually 50 hertz; taking into account the maximum frequency change rate limit and the maximum power change amount in the system;
the minimum inertia constant limit of the system is calculated according to equation 7:
wherein: h min The minimum inertia constant limit value of the system is expressed in seconds; ΔP max The maximum power variation which can occur when the system is disturbed is expressed in megawatts; df (df) max And/dt is the maximum rate of change of frequency allowed by the regional power grid, and is expressed in hertz/second.
5. The method according to claim 1, wherein the obtaining of the flexible resource in S3 considers the flexible resource in the area and the flexible resource situation in the adjacent area, considers the potential of resource complementation by the tie line, and the flexible resource in different forms considers the related technical economic parameter in analysis.
6. A high-proportion new energy system inertia constrained flexible resource allocation system, comprising:
the flexibility demand module is used for acquiring flexibility demands of the load-based and intermittent new energy power generation computing system under different time scales;
the constraint index module is used for acquiring actual running state data of the high-proportion new energy system, dynamically calculating the inertia and the minimum inertia limit value of the system according to the actual running state data, and taking the minimum inertia limit value as a constraint index of flexible resource allocation of the high-proportion new energy system;
the flexible resource module is used for acquiring flexible resources which can provide flexible technology for the high-proportion new energy system from the angles of power supply, power grid, load and energy storage;
and the joint optimization module is used for performing joint optimization on the flexible resources under the condition of considering the flexible requirements, and the joint optimization meets constraint indexes of flexible resource allocation of the high-proportion new energy system.
7. The system of claim 7, wherein the flexibility requirement module is specifically configured to:
s11, obtaining a difference value between the daily payload of each hour in a day and the average value of the daily payload as a daily flexibility requirement;
s12, obtaining a difference value between a daily net load average value in a week and a week net load average value as a week flexibility requirement;
s13, obtaining the difference value between the average value of the net load of each month in one year and the average value of the net load in one year as the annual flexibility requirement.
8. The system of claim 7, wherein the constraint index module obtains actual operating state data of the high-proportion new energy system specifically comprises:
acquiring time sequence production data of the regional power grid in a preset time range, wherein the time sequence production data comprises the following steps: grid data and power generation data; the grid data includes: grid topology, node load, system total load, maximum frequency rate of change limit, and maximum power absence, the power generation data comprising: the installed capacity of each synchronous generator and each new energy station, the real-time generation power, the rotational kinetic energy of the generator and the virtual inertia constant.
9. The system of claim 8, wherein the constraint index module dynamically calculates inertia and minimum inertia limits of the system based on the actual operating state data comprises:
acquiring the total capacity of the synchronous generators in the starting state and the new energy stations in the grid-connected power generation state in the regional power grid through a formula 1 according to the installed capacity of each synchronous generator and each new energy station;
wherein S is sys The total capacity of all the synchronous generators started up and all the new energy stations for grid-connected power generation in the regional power grid is in megawatts; s is S Geni The unit is megawatt for the installed capacity of the synchronous generator i; s is S Re,k The unit is megawatt for the installed capacity of the new energy station k; x is x i For the on-off state of synchronous generator i, x i When the power is equal to 0, the power is turned off, and when the power is equal to 1, the power is turned on; x is x k Is in a grid-connected power generation state of a new energy station k, x k When the power is equal to 0, the power is not generated when the power is stopped, and when the power is equal to 1, the power is generated when the power is connected with the grid; n (N) Gen The total number of synchronous generators in the regional power grid; n (N) Re The total number of new energy stations in the regional power grid;
according to the generator rotation kinetic energy and the installed capacity of each synchronous generator, the inertia constant of each unit of each type in the network is obtained through a formula 2:
wherein: h i The inertia constant of the synchronous generator i is expressed in seconds; e (E) MWS,i The unit is megawatt-second which is the generator kinetic energy of the synchronous generator i; the synchronous generator comprises a generator and a water turbine or a steam turbine;
according to the rotational kinetic energy of all the started synchronous generators in the system, the total system running inertia level of the regional power grid at a certain running time is obtained through a formula 3:
wherein: i sys The total inertia level of the system at the running time is expressed in megawatts-seconds;
calculating the total running inertia constant of the system of the regional power grid at a certain running time according to the inertia constant of the synchronous generator in the starting state and the installed capacity of the synchronous generator by the formula 4:
wherein: h op The real-time running inertia constant of the system is given in seconds;
according to the rotational inertia of the traditional synchronous generator and the virtual inertia of the new energy station, the system operation inertia constant of the regional power grid at a certain operation time is obtained through a formula 5:
wherein: h VI The real-time running inertia constant of the system taking the virtual inertia of the new energy into consideration is expressed in seconds; h k The virtual inertia constant of the new energy station k is given in seconds;
obtaining the frequency change rate of the system through a formula 6:
wherein: df/dt is the rate of change of the system frequency in hertz/second; Δp is the amount of power change in megawatts when a disturbance occurs to the system; f (f) N Is the rated frequency of the system, and is expressed in hertz, usually 50 hertz; taking into account the maximum frequency change rate limit and the maximum power change amount in the system;
the minimum inertia constant limit of the system is calculated according to equation 7:
wherein: h min The minimum inertia constant limit value of the system is expressed in seconds; ΔP max The maximum power variation which can occur when the system is disturbed is expressed in megawatts; df (df) max And/dt is the maximum rate of change of frequency allowed by the regional power grid, and is expressed in hertz/second.
10. The system of claim 7, wherein the flexible resource module is specifically configured to:
when the flexibility resources are acquired, the flexibility resources of the area and the flexibility resources of the adjacent areas are considered, the potential of resource complementation through the connecting lines is considered, and the related technical and economic parameters are considered when the flexibility resources in different forms are analyzed.
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| CN118052576A (en) * | 2024-04-16 | 2024-05-17 | 广东工业大学 | A multi-level inertia market transaction method and system considering user demand elasticity |
| CN118095790A (en) * | 2024-04-23 | 2024-05-28 | 中国电建集团昆明勘测设计研究院有限公司 | A method and system for configuring hydropower station resources based on multi-source equipment status |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN118052576A (en) * | 2024-04-16 | 2024-05-17 | 广东工业大学 | A multi-level inertia market transaction method and system considering user demand elasticity |
| CN118095790A (en) * | 2024-04-23 | 2024-05-28 | 中国电建集团昆明勘测设计研究院有限公司 | A method and system for configuring hydropower station resources based on multi-source equipment status |
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