Disclosure of Invention
In order to solve the defects of the prior art, the invention provides a dynamic power grid capacity margin configuration method and system based on source load storage interaction, provides a planning operation integrated multi-time scale network side equipment capacity margin configuration strategy, synthesizes the interaction characteristics of source load storage and multi-time scale capacity margin configuration results, forms a planning operation integrated power grid capacity margin configuration scheme based on source load storage interaction, and greatly improves the accuracy of configuration results.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
in a first aspect, the invention provides a dynamic configuration method for a power grid capacity margin based on source load storage interaction.
A power grid capacity margin dynamic configuration method based on source load storage interaction comprises the following steps:
performing capacity margin planning under a first-stage time scale to obtain a planning result of capacity configuration of a source load storage side, and performing network side capacity margin configuration under a second-stage time scale and network side capacity margin configuration under a third-stage time scale by taking the annual capacity margin planning result as an initial value; wherein, the time granularity of the first stage, the second stage and the third stage time scale is gradually decreased;
correcting the network side capacity margin configuration result under the second-level time scale by using the network side capacity margin configuration result under the third-level time scale, using the corrected network side capacity margin configuration result under the second-level time scale, combining the planning result of the source load storage side capacity configuration as the initial value of the capacity margin planning under the first-level time scale, and executing rolling optimization to obtain the annual network side equipment capacity margin configuration result.
As a further limitation of the first aspect of the present invention, a planning solution of source load storage side capacity configuration under a first level time scale is obtained by taking the minimum total cost of the planning year as a first objective function, and the planning solution is used as a planning result of the source load storage side capacity configuration;
respectively taking the planning solutions as initial values of a second objective function to obtain optimal solutions of network side capacity margin configuration under a second-stage time scale;
taking the planning solution as a third objective function initial value to obtain an optimal solution of network side capacity margin configuration under a third-level time scale, wherein the time granularity of the first-level time scale is annual, the time granularity of the first-level time scale is hour, and the time granularity of the first-level time scale is minute;
correcting the optimal solution of the network side capacity margin configuration under the second-level time scale by using the optimal solution of the network side capacity margin configuration under the third-level time scale;
and performing rolling optimization by combining the optimal solution of the network side capacity margin configuration under the corrected second-stage time scale with the planning solution of the source load storage side capacity configuration under the first-stage time scale to serve as an initial value of a new first objective function, so as to obtain a year-by-year network side equipment capacity margin configuration result.
As a further limitation of the first aspect of the present invention, the total cost of the planning year in the first objective function is: the addition of various power generation technologies, annual initial investment costs of new or modified lines, operational maintenance costs, fuel costs and power transmission costs.
As a further limitation of the first aspect of the invention, the second objective function and the third objective function are: the sum minimum of the grid running cost, the power generation capacity standby cost and the line capacity standby cost;
the operation cost is as follows: the electricity purchasing cost, the energy storage running cost, the controllable distributed power supply running and starting cost, the demand response cost and the reactive compensator running cost are added;
the spare cost of the power generation capacity is the spare cost provided by a power grid, a controllable distributed power supply, energy storage and demand response.
As a further definition of the first aspect of the invention, the second objective function and the third objective function each comprise: node power balance constraint, line power flow constraint, power flow limit constraint, distributed power supply output limit constraint, distributed power supply available reserve limit constraint, distributed power supply climbing limit constraint, power supply output limit constraint, energy storage related constraint, demand response limit constraint, reactive compensation related constraint and reserve demand constraint.
As a further definition of the first aspect of the invention, the first objective function comprises: power demand constraints, actual operating capacity constraints, and power generation installed capacity constraints.
In a second aspect, the invention provides a power grid capacity margin dynamic configuration system based on source load storage interaction.
A power grid capacity margin dynamic configuration system based on source load storage interaction, comprising:
a capacity margin configuration unit configured to: performing capacity margin planning under a first-stage time scale to obtain a planning result of capacity configuration of a source load storage side, and performing network side capacity margin configuration under a second-stage time scale and network side capacity margin configuration under a third-stage time scale by taking the annual capacity margin planning result as an initial value; wherein, the time granularity of the first stage, the second stage and the third stage time scale is gradually decreased;
a scroll optimization configuration unit configured to: correcting the network side capacity margin configuration result under the second-level time scale by using the network side capacity margin configuration result under the third-level time scale, using the corrected network side capacity margin configuration result under the second-level time scale, combining the planning result of the source load storage side capacity configuration as the initial value of the capacity margin planning under the first-level time scale, and executing rolling optimization to obtain the annual network side equipment capacity margin configuration result.
As a further limitation of the second aspect of the present invention, the total cost of the planned year is minimum as the first objective function, so as to obtain a planning solution of the source load storage side capacity configuration under the first level time scale, and the planning solution is used as a planning result of the source load storage side capacity configuration;
respectively taking the planning solutions as initial values of a second objective function to obtain optimal solutions of network side capacity margin configuration under a second-stage time scale;
taking the planning solution as a third objective function initial value to obtain an optimal solution of network side capacity margin configuration under a third-level time scale, wherein the time granularity of the first-level time scale is annual, the time granularity of the first-level time scale is hour, and the time granularity of the first-level time scale is minute;
correcting the optimal solution of the network side capacity margin configuration under the second-level time scale by using the optimal solution of the network side capacity margin configuration under the third-level time scale;
and performing rolling optimization by combining the optimal solution of the network side capacity margin configuration under the corrected second-stage time scale with the planning solution of the source load storage side capacity configuration under the first-stage time scale to serve as an initial value of a new first objective function, so as to obtain a year-by-year network side equipment capacity margin configuration result.
In a third aspect, the present invention is a computer readable storage medium, on which a program is stored, which when executed by a processor implements the steps in the method for dynamically configuring grid capacity margins based on source load storage interactions according to the first aspect of the present invention.
In a fourth aspect, the present invention provides an electronic device, including a memory, a processor, and a program stored in the memory and executable on the processor, where the processor implements the steps in the method for dynamically configuring a grid capacity margin based on source load storage interaction according to the first aspect of the present invention when the program is executed by the processor.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention creatively provides a planning and running integrated multi-time-scale network side equipment capacity margin configuration strategy, integrates the interaction characteristics of source load storage and the multi-time-scale capacity margin configuration result, forms a planning and running integrated power grid capacity margin configuration scheme based on source load storage interaction, and greatly improves the accuracy of the configuration result.
2. According to the invention, the network side capacity margin configuration result under the corrected second-stage time scale is combined with the planning result of the source load storage side capacity configuration as the initial value of capacity margin planning under the first-stage time scale, and the rolling optimization is executed, so that the annual network side equipment capacity margin configuration result is obtained, the multi-time scale combined rolling optimization is realized, and the configuration accuracy is further improved.
Additional aspects of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Detailed Description
The invention will be further described with reference to the drawings and examples.
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
Embodiments of the invention and features of the embodiments may be combined with each other without conflict.
Example 1:
according to the method, under the condition that the operation cost of a conventional unit, the operation cost of an energy storage power station, the new energy electricity discarding cost, the electricity discarding punishment cost of a load side and the line transmission cost are considered, an optimal configuration model of capacity margin of power grid equipment is established, a model simplification method is provided, and a rapid solving method is designed to achieve efficient solving of the network side capacity margin configuration model taking the interaction characteristics of source and load into account; meanwhile, the invention provides a multi-time scale network side equipment capacity margin configuration method of 'planning operation integration'; finally, integrating interaction characteristics of source load storage and multi-time scale capacity margin configuration results to form a planning operation integrated power grid capacity margin configuration strategy based on source load storage interaction, and specifically comprising the following steps:
s1: a network side flexibility margin configuration method based on source load storage interaction.
According to the invention, a quantized relation between active power capacity and reactive power capacity is provided by establishing a power grid voltage and power regulation capacity lifting way, and an optimal capacity margin is configured for power grid transmission equipment, so that a source side power distribution network and a platform region micro-grid can stably and interactively support a power grid accessed by user side adjustable resource energy sources such as a charging facility, an electric automobile and the like.
S1.1: an objective function.
The objective function is to minimize grid operating costs, power generation capacity reserve costs, and line capacity reserve. The running cost comprises electricity purchasing cost, energy storage running cost, controllable distributed power supply running and starting cost, demand response cost and reactive compensator running cost. The spare cost of the power generation capacity comprises the spare cost provided by a power grid, a controllable distributed power supply, energy storage and demand response:
(1);
wherein,、/>and->The specific expression of (2) is as follows:
(2);
(3);
(4)
in the method, in the process of the invention,,/>the total operation cost and the standby cost of the power distribution network are respectively represented; />,/>,/>,/>,/>,/>,/>,/>,/>,/>,/>Respectively are related toA coefficient of running cost; />,/>,/>,/>Coefficients respectively representing the associated standby costs of power generation; />A coefficient representing the spare cost of the associated line capacity; />,/>Representing the active and reactive power purchased to the upper grid; />,/>Respectively representing the charge and discharge power of the stored energy; />,/>Active and reactive power of the distributed power supply are respectively represented; />Is a binary variable, and indicates whether the distributed power supply is started (the starting is 1, otherwise, the starting is 0); />Active power representing demand response; />,/>Representing the reactive power of the capacitor bank and the static var compensator, respectively; />,/>Respectively representing climbing up and climbing down provided by an upper power grid for standby; />,/>Respectively representing climbing up and climbing down provided by the controllable distributed power supply for standby; />,/>Respectively representing the climbing up and climbing down provided by energy storage for standby; />Indicating that the demand response provides redundancy; />Representing the duration of the time interval; />,/>Respectively representing a set of times and a set of grid nodes; />Representation lineijCapacity of the new (retrofit).
S1.2: constraint conditions.
(1) Node power balance type:
(5);
(6);
in the method, in the process of the invention,representing slave nodesiTo the nodejIs an active power flow of (a); />Indicating time of daytNodeiAn upper active load; />,,/>Respectively representing a set of energy storage nodes, load nodes and demand response nodes; />Representing reactive load.
(2) Line tide formula:
(7);
in the method, in the process of the invention,representation oftTime nodeiIs set to the voltage amplitude of (1); />Representing the phase angle difference between the line head end node and the line tail end node; />,/>Respectively represent linesijAnd susceptance.
(3) Load flow restriction:
(8);
in the method, in the process of the invention,representation lineijMaximum capacity of (2); />Representation lineijCapacity of the new (retrofit).
(4) Distributed power supply output limits.
The following formula limits the distributed power supply output variation to a certain range:
(9);
(10);
in the method, in the process of the invention,is a binary variable, representingtTime distributed power supplyiWhether or not to be online; />,/>Respectively represent distributed power suppliesiMaximum and minimum output limits of (2); />Representing distributed power suppliesiMaximum apparent power of (a).
(5) The distributed power supply may provide backup limits:
(11);
(12);
in the method, in the process of the invention,,/>representing the up-and-down-climbing rate of the distributed power supply; />Indicating the length of the corresponding time scale at time t.
(6) The climbing limit of the distributed power supply, the output change of the unit is limited by the climbing speed:
(13);
(14);
in the method, in the process of the invention,and->Respectively representing the output of the initial state of the unit i and the output of the first moment,/>The start-stop state of the unit i is shown, the start-up time is 1, and the stop time is 0.
(7) Power supply output limit constraints:
(15);
(16);
(17);
in the method, in the process of the invention,representing a predicted value and a maximum output value of the power supply; />Representing the power factor angle of the power supply; />,Representing the maximum and minimum values of the power factor angle, respectively.
(8) The energy storage is related to constraint, the energy stored by the energy storage is in the upper and lower limit ranges, the charging or discharging power of the energy storage is in the upper limit range, and the energy storage can only be charged or discharged at the same time:
(18);
(19);
(20);
(21);
(22);
(23);
(24);
(25);
in the method, in the process of the invention,,/>respectively representing the maximum and minimum energy values of the stored energy; />Representation oftStoring energy at any time; />And->Respectively representing an initial value and a final value of the stored energy; />,/>Respectively representing the charge and discharge power of the stored energy; />,/>Is a binary variable, and the values of 1 and 0 respectively indicate that the energy storage is in a charging state and a discharging state;,/>respectively representing an upper limit of charging power and an upper limit of discharging power of the stored energy; />And->Respectively charging and discharging efficiency; />,/>Respectively represent the discharge and charge speeds of the stored energy.
(9) Demand response limits:
(26);
(27);
in the method, in the process of the invention,indicating whether the demand response is at a nodeiOn (I)>Representing the maximum proportion of demand response to the total load of the node.
(10) Reactive compensation-related constraints:
(28);
(29);
in the method, in the process of the invention,is a binary variable, representingtTime of day (time)iThe first capacitor in the capacitor bank on the individual nodekWhether the capacitors are put into use; />Reactive power for each capacitor; />Representing the number of capacitors in the capacitor bank; />Representing the maximum number of capacitor switching in a certain time.
(30);
(31);
In the method, in the process of the invention,,/>representing the minimum and maximum power of the static var compensator, respectively.
(11) Standby demand constraint:
(32);
(33);
in the middle of,/>Respectively representing the active climbing standby requirement and the active climbing standby requirement; />,And the reactive climbing standby requirement and the active climbing standby requirement are respectively indicated.
S1.3: model linearization method.
(1) A linearization method for the output cost of a unit.
The quadratic term in the unit output cost function isIt is now necessary to convert it into a piecewise linear function:
(34);
wherein:
(35);
in the method, in the process of the invention,the output of the unit i on the mth section is represented; />And->Respectively representing upper and lower boundary values of an mth segmented output section of the unit i; />And->Respectively represent the units iMaximum and minimum force.
(2) And linearizing a line tide formula.
The original line flow formula is an alternating current flow constraint expression form containing quadratic terms and sine quantities, the voltage amplitude of each node is approximately 1 on the premise of neglecting network loss, and the phase angle difference of the nodes at two ends of the line is approximately 0, so that,,/>,/>The method can obtain:
(36);
(3) And linearizing branch power flow constraint and distributed power supply output limit.
The branch flow constraint is similar to the formula form of the distributed power supply output, and from the geometric point of view, the feasible domains are all with the radius ofS ij The invention carries out equivalent linearization representation on the power circle interior, and according to the basic method of analytic geometry, the area surrounded by inscribed regular polygons can be represented by a series of linear constraints as follows:
(37);
in the method, in the process of the invention,the coefficient corresponding to the linear power circle constraint varies with the number of sides of the divided regular polygon.
In consideration of the compromise between precision and calculation efficiency, the model equally divides the circumference 12, and sequentially connects the division points to obtain a circular inscribed dodecagon, as shown in fig. 1, that is, the area enclosed by the inscribed dodecagon is approximately replaced by the area enclosed by the circular inscribed dodecagon, and specifically, as shown in fig. 2. Assuming A, B as two adjacent points of regular dodecagon in the circle, the radian angles of A, B are α and β respectively, then:
(38);
the A point coordinates areThe coordinates of the point B are +.>The straight line equation for any one side AB of a right dodecagon within a circle can be expressed as:
(39);
based on analytical geometry theory, the formula can be:
(40);
(4) The Big-M method processes reactive compensation constraint.
The reactive power sent by the capacitor bank is the sum of all switched capacitor reactive power; the number of the switched capacitors at a certain moment is limited by the number of the capacitors in the capacitor bank; the number of times the capacitor bank is switched is limited within a certain time.
(41);
In the constraint group, the nonlinear term is obtained by multiplying a discrete variable by a continuous variable, and linearizing the discrete variable according to a Big-M method, wherein the following formula is shown as follows:
(42);
wherein,M 1 is a very large constant.
S2: the planning operation integrated network side equipment capacity margin dynamic configuration method.
The invention provides an integrated decision model integrating three modules of long-term planning, short-term scheduling and real-time scheduling, which considers multi-time granularity in power grid capacity margin configuration from the angles of three time scales of long term, short term and real time, wherein the time granularity of the first-stage time scale is 1 year, and long-term annual capacity margin planning is realized; the time granularity of the second-stage time scale is 1 hour, so that the short-term scheduling optimization of 8760 hours in each planning year is realized; and the time granularity of the residual time scale is 15min, so that the ultra-short-term flexibility margin operation capability is optimized. The model operates dynamically, and decision variables (such as newly-increased capacity and actual output of a generator set, an energy storage power station and a distributed power supply) of each time interval are optimized each time, the capacity of a network side newly-increased (transformed) line and the capacity of the newly-increased line are newly-increased, only the result of a first stage time scale is used as a planning instruction, the strong constraint force is provided, the result of the rest time scales is used as a correction basis, and the planning decision result of the first stage is further perfected, as shown in fig. 3.
The planning and scheduling independent model is converted into an integrated model, and various constraints under different time granularities are required to be changed into constraints under variable time granularities.
S2.1: a multi-time scale dynamic model.
The first-stage time scale model takes the minimum sum of the costs of all years in different stages as an objective function, and comprises all power generation technologies, the initial investment cost of the newly added (reformed) line years, and the operation and maintenance cost.
(43);
Wherein,TCrepresenting the total cost of planning a year,、/>representing the investment costs of the new additions (modifications) of the generator set and the network-side lines, respectively,/->、/>Representing the operating and maintenance costs of the generator set and the network side line respectively,Nrepresenting a set of power generation technology types,N i representing a set of newly added (rebuilt) lines;
wherein, investment cost:
(44);
wherein,representing the unit investment cost of newly built (or improved) generator sets or line capacities; />Representing total newly built (or improved) capacity; />Representing an internal rate of return; />Life cycle of the technique, ">"indicates the subscript i or line ij of the unit.
Operation and maintenance costs:
(45);
wherein,representation ofRunning and maintaining cost coefficients of the unit and the line; />Representing the actual running installed capacitySet to 1); />Indicating the number of actual operating hours.
The constraint conditions of the first-stage time scale model mainly comprise power demand constraint, actual operation capacity constraint (the installed capacity of each generator set in actual operation every year is smaller than the technical stock quantity of the technology in the current year, wherein the technical stock quantity refers to the sum of the installed capacity of the technology in the previous year and the newly built (or improved) capacity under consideration of depreciation, and the installed capacity subjected to forced elimination), power generation installed capacity constraint (according to economic society development situation and environmental resource limitation, upper and lower limits exist on the installed capacities of different generator sets, the installed capacity of new energy power generation technology and distributed power sources popularized by policies is higher than the capacity of the reference year within the allowable range of physical resource capacity, the installed capacity of the technology in the next year is lower than the capacity of the reference year for the obsolete capacity, line capacity limitation constraint and the like.
The second and third time scale models are network side flexibility margin configuration models based on source load storage interaction in S1, and it is noted that the time length T in the models needs to be replaced by a variable time scale parameter T h (h is 1 and 2 times T 1 And T 2 Respectively 1 hour and 15 minutes).
S2.2: and (5) dynamically configuring the capacity margin of the power grid.
According to the regional power system development prediction result, a planning layer model of a first-stage time scale is operated, a planning solution of source load storage side capacity configuration is solved, the solution value is substituted into a second-layer scheduling layer optimization model and a third-layer scheduling layer optimization model as an initial value, and an optimal solution of network side capacity margin configuration is solved; and taking the optimal solution as a correction value of the capacity margin solution of the network side equipment in the first-layer planning model, forming a new planning model initial value together with the planning solution of the capacity configuration of the source load storage side and the like, operating the first-layer planning model, solving to obtain the planning solution of the second year, performing rolling optimization, and finally obtaining the capacity margin configuration optimal solution of the network side equipment year by year.
Example 2:
the embodiment 2 of the invention provides a dynamic configuration system for power grid capacity margin based on source load storage interaction, which comprises the following components:
a capacity margin configuration unit configured to: performing capacity margin planning under a first-stage time scale to obtain a planning result of capacity configuration of a source load storage side, and performing network side capacity margin configuration under a second-stage time scale and network side capacity margin configuration under a third-stage time scale by taking the annual capacity margin planning result as an initial value; wherein, the time granularity of the first stage, the second stage and the third stage time scale is gradually decreased;
a scroll optimization configuration unit configured to: correcting the network side capacity margin configuration result under the second-level time scale by using the network side capacity margin configuration result under the third-level time scale, using the corrected network side capacity margin configuration result under the second-level time scale, combining the planning result of the source load storage side capacity configuration as the initial value of the capacity margin planning under the first-level time scale, and executing rolling optimization to obtain the annual network side equipment capacity margin configuration result.
The working method of the system is the same as the power grid capacity margin dynamic configuration method based on source load storage interaction provided in embodiment 1, and will not be described here again.
Example 3:
embodiment 3 of the present invention provides a computer readable storage medium having a program stored thereon, which when executed by a processor, implements the steps in the method for dynamically configuring a grid capacity margin based on source load storage interaction according to embodiment 1 of the present invention.
Example 4:
the embodiment 4 of the invention provides an electronic device, which comprises a memory, a processor and a program stored on the memory and capable of running on the processor, wherein the processor realizes the steps in the dynamic configuration method of the grid capacity margin based on the source load storage interaction according to the embodiment 1 of the invention when executing the program.
The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.