Multivariate resource inertia and primary frequency modulation auxiliary service sequence acquisition method and system

Abstract

The invention relates to the technical field of safe and stable operation of a power system, in particular to a method and a system for acquiring a multi-element resource inertia and a primary frequency modulation auxiliary service sequence. Multi-element subject day-ahead electric energy market pre-clearing is carried out; performing system frequency safety verification; calculating inertia and primary frequency modulation vacancy required by the frequency safety of the system according to a time period in which the frequency safety is not met; performing optimization acquisition of the network construction type energy storage inertia and the primary frequency modulation auxiliary service; performing optimization acquisition of inertia and primary frequency modulation auxiliary service of the conventional unit; and carrying out multi-element subject day-ahead electric energy market official clearing, and carrying out day-ahead electric energy market clearing optimization calculation under the determined startup mode. System frequency safety checking is carried out on the basis of pre-clearing of a multi-element main body electric energy market, inertia and primary frequency modulation vacancy are calculated for the time period when system frequency safety is not met, and inertia and primary frequency modulation services are provided for obtaining the inertia and the primary frequency modulation vacancy, coordinating and synchronizing a generator set, energy storage, new energy and other main bodies.

Description

Technical Field

[0001] The present invention relates to the technical field of safe and stable operation of electric power systems, and in particular to a method and system for sequentially acquiring multi-resource inertia and primary frequency regulation auxiliary services. Background Art

[0002] In the process of energy transformation to low-carbon, renewable energy has gradually replaced traditional thermal power units, resulting in significant changes in the structure and operating characteristics of the power system. The traditional inertia and primary frequency regulation levels in the system have gradually decreased, posing a challenge to the frequency safety and stability of the power system. In the past, synchronous generators were mainly used to provide inertia and primary frequency regulation responses, but now energy storage and new energy resources can also provide inertia and primary frequency regulation to support grid frequency stability by simulating the rotor motion equations of synchronous generator sets and presenting voltage source control to the outside world. Therefore, it is possible to consider incorporating virtual inertia and primary frequency regulation provided by energy storage and new energy into market acquisition, and explore a way to stimulate the supply of energy storage and new energy inertia and primary frequency regulation resources. How to effectively coordinate synchronous generator sets, energy storage, new energy and other entities to provide inertia and primary frequency regulation services requires studying the sequential acquisition of multi-resource inertia and primary frequency regulation auxiliary services. Summary of the invention

[0003] In view of the problems existing in the prior art, the present invention is proposed.

[0004] Therefore, the problem to be solved by the present invention is how to solve the technical problem of competing for the inertia and primary frequency regulation auxiliary services provided by multiple entities on the same platform to maintain the safety and stability of the power grid frequency under large disturbance conditions.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] In a first aspect, an embodiment of the present invention provides a method for sequentially acquiring multi-resource inertia and primary frequency regulation auxiliary services, which includes carrying out pre-clearing of the day-ahead electric energy market of multiple entities;

[0007] Perform system frequency safety check. If the frequency safety requirements are met, proceed to the final step. If not, proceed to the next step.

[0008] For the period when frequency safety is not met, calculate the inertia and primary frequency regulation shortfall required for system frequency safety;

[0009] Optimize the acquisition of grid-type energy storage inertia and primary frequency regulation auxiliary services. If the acquired inertia and primary frequency regulation meet the shortfall, proceed to the final step. If not, proceed to the next step.

[0010] Optimize the inertia of conventional units and primary frequency regulation auxiliary services;

[0011] Carry out formal clearing of the day-ahead electricity energy market involving multiple entities, and perform optimization calculations for clearing the day-ahead electricity energy market under a determined startup method.

[0012] As a preferred solution of the method for sequentially acquiring the multi-resource inertia and primary frequency regulation auxiliary services of the present invention, wherein: the pre-clearing of the day-ahead electric energy market based on the multi-subjects, including energy storage and new energy, has a grid-following type and a grid-building type;

[0013] The virtual inertia and inertia support power provided by the grid-type energy storage are shown in the following formulas:

[0014]

[0015] in, are the virtual inertia of the grid-type energy storage i in charging and discharging states, MWs; It is a grid-type energy storage collection; is the inertia time constant of the grid-type energy storage i, s; They are the maximum charging and discharging power of grid-type energy storage i respectively; are the inertia support power of the grid-type energy storage i in charging and discharging states; RoCoF max It is the maximum frequency change limit allowed after the system is disturbed; f0 is the rated frequency of the system;

[0016] The virtual inertia and inertia support power provided by the network-building new energy are shown in the following formulas:

[0017]

[0018] Among them, I ne,i is the virtual inertia of the grid-connected new energy unit i, MWs; is the inertia time constant of the grid-connected new energy unit i, s; P ne,i,max is the rated power of the grid-connected new energy unit i; To build a network of new energy units; The inertia support power of the network-type new energy i;

[0019] Construct a multi-subject day-ahead market pre-clearing model;

[0020] Objective function:

[0021]

[0022] Where T is the total number of time periods, 24 or 96; N g is the total number of conventional units; is the grid-connected energy storage set; M is the total number of conventional unit quotation segments; ρ i,m The power quotation for the mth section of conventional unit i; are the charging and discharging quotations of energy storage i respectively; P i,m,t is the active power of the mth section of the conventional unit i in time period t; are the charging and discharging power of energy storage i in time period t; u i,t is the start-stop state variable of conventional unit i in period t, u i,t =1 means power on, u i,t =0 means shutdown; is the startup cost of conventional unit i;

[0023] Constraints:

[0024] (1) System load power balance constraints:

[0025]

[0026] in, For the grid-based new energy collection; P g,i,t is the active power of conventional unit i in period t; P ne,i,t is the active power of the new energy unit i in period t; P load,t is the system active load during period t;

[0027] (2) System spare capacity constraints:

[0028]

[0029] Among them, P g,i,max , P g,i,min are the maximum and minimum active power of conventional unit i respectively; R t,up , R t,dn are the upper and lower reserve capacity requirements of the system in period t respectively;

[0030] (3) Network security constraints:

[0031]

[0032] Among them, N bus is the number of system nodes; N b is the number of lines; P l,max is the active power transmission limit of line l; G j,l is the power transfer factor of node j to line l; P g,j,t , P ne,j,t are respectively the active power of the conventional unit and the new energy unit at node j in period t; are the energy storage charging and discharging power at node j during period t; P load,j,t is the active load on node j during period t;

[0033] (4) Output constraints of conventional units:

[0034] u i,t P g,i,min ≤P g,i,t ≤u i,t P g,i,max i=1,2,…,N g ; t=1,2,…,T

[0035] (5) Conventional unit climbing constraints:

[0036]

[0037] Among them, ΔP i,dn , ΔP i,up are the maximum downward and upward climbing amounts of conventional unit i in a single period, respectively;

[0038] (6) Minimum continuous start and stop time constraints for conventional units:

[0039]

[0040] Among them, T i,t,up , T i,t,dn are the continuous start and stop times of conventional unit i in period t; T i,up , T i,dn are the minimum start and stop time requirements of conventional unit i respectively;

[0041] (7) Output constraints of new energy units:

[0042]

[0043] in, is the active power prediction of new energy unit i in period t; Reserve capacity for primary frequency regulation of grid-connected renewable energy i, MW;

[0044] (8) Energy storage charging and discharging power constraints:

[0045]

[0046] in, are respectively energy storage i in t 0-1 variable of the charge and discharge state of the time period, Indicates that it is in charging state. Indicates that it is in the discharge state; Reserve capacity for primary frequency regulation of grid-type energy storage i;

[0047] (9) Energy storage charge state constraints:

[0048]

[0049] Among them, S s,i,t B is the state of charge of energy storage i in period t; s,i is the rated capacity of energy storage i; are the charging and discharging efficiencies of energy storage i; Δt is a time interval; S s,i,min , S s,i,max are the minimum and maximum capacities of energy storage i under stable operation, respectively; is the reserved energy of grid-type energy storage i in period t; S s,i,0 , S s,i,T are the initial and final values ​​of the state of charge of energy storage i respectively; The expression is as follows:

[0050]

[0051] in, and They are the energy required to be reserved for inertia and primary frequency regulation services provided by the grid-connected energy storage i during period t; T s,ramp It is the complete response time of primary frequency regulation of grid-type energy storage.

[0052] As a preferred solution of the method for sequentially acquiring the multi-resource inertia and primary frequency modulation auxiliary service of the present invention, wherein: the system frequency safety check is performed, if the frequency safety requirements are met, the final step is entered, if not, the next step is entered; the check steps are as follows:

[0053] The power shortage of power shortage type fault in each period is defined as P loss,t =λP load,t , λ is the power disturbance ratio; the maximum frequency deviation allowed by the system when a disturbance occurs is specified as Δf max ;

[0054] Calculate the maximum sum of primary frequency regulation capacity and the sum of inertia that can be provided by conventional units, energy storage and new energy in each period obtained in step 1. Here, step 1 represents the pre-clearing of the multi-subject day-ahead electricity energy market;

[0055] (1) When the frequency deviation is Δf max During disturbance, the primary frequency regulation capacity provided by a single conventional unit is as follows:

[0056]

[0057] in, The frequency deviation is Δf max During disturbance, the primary frequency regulation capacity provided by conventional unit i; K g,iis the droop coefficient of conventional unit i, MW / Hz; Reserve capacity for primary frequency regulation of conventional unit i;

[0058] When the frequency deviation is Δf max When there is a disturbance, the primary frequency regulation capacity that a single grid-connected energy storage can provide is:

[0059]

[0060] in, The frequency deviation is Δf max When there is a disturbance, the primary frequency regulation capacity provided by the grid-type energy storage i; K s,i is the virtual droop coefficient of the grid-type energy storage i, MW / Hz;

[0061] When the frequency deviation is Δf max When there is a disturbance, the primary frequency regulation capacity that a single grid-connected new energy unit can provide is:

[0062]

[0063] in, The frequency deviation is Δf max When there is a disturbance, the primary frequency regulation capacity provided by the grid-connected renewable energy source i; K ne,i is the virtual droop coefficient of the grid-connected new energy unit i, MW / Hz;

[0064] Then, the conventional units, energy storage and new energy units in each period obtained in step 1 will have a frequency deviation of Δf max During a disturbance, the maximum total primary frequency modulation capacity that can be provided in each period is:

[0065]

[0066] in, The frequency deviation during period t is Δf max When there is a disturbance, the total primary frequency modulation capacity that the system can provide is obtained from step 1; Ω g1,t , are respectively the sets of conventional units, grid-connected energy storage units, and grid-connected new energy units started up in step 1 during time period t;

[0067] (2) According to the system operation status obtained in step 1, the total inertia of the system in each period is:

[0068]

[0069] Among them, I 1,t for t The sum of the system inertia obtained in step 1 during the period; is the inertia time constant of conventional unit i, s;

[0070] Will I 1,t Substitute it into the three major frequency safety constraints for verification; the three major constraints are frequency change rate constraint, frequency minimum point constraint, and quasi-steady-state frequency constraint;

[0071] The three frequency safety constraints are as follows:

[0072] (1) Frequency change rate constraint:

[0073]

[0074] Among them, I sys,t is the inertia of the system in period t;

[0075] (2) Frequency minimum point constraint:

[0076]

[0077] in, is the primary frequency regulation capacity of the system in period t; T g,ramp T is the complete response time of a conventional unit frequency modulation, which generally takes 10 to 20 seconds; del It is the primary frequency regulation response delay of conventional units, which is generally less than 3s;

[0078] (3) Quasi-steady-state frequency constraint:

[0079]

[0080] Specific verification method: Substitution I 1,t Substitute I sys,t If all three constraints are met, the system meets the frequency safety requirements in all time periods; if one of the constraints is not met, it indicates that the system inertia and primary frequency regulation capacity in time period t are insufficient, and it is necessary to obtain inertia and primary frequency regulation auxiliary services.

[0081] As a preferred solution of the method for sequentially acquiring the multi-resource inertia and primary frequency regulation auxiliary services of the present invention, the method of calculating the inertia and primary frequency regulation shortage required for system frequency safety based on the period when frequency safety is not satisfied comprises the following process:

[0082] Calculate the system's minimum primary frequency modulation requirement and inertia requirement;

[0083] After a large disturbance occurs, the system frequency needs to return to a quasi-steady state, so at least the quasi-steady state constraint must be met. Then the minimum frequency modulation capacity requirement of the system is:

[0084]

[0085] The minimum inertia requirement of the system is calculated based on the frequency change rate constraint:

[0086]

[0087] in, The minimum inertia requirement of the system considering the frequency change rate constraint in period t;

[0088] According to the frequency minimum point constraint, when Taking the minimum value, the right side of the formula has the maximum value, so the minimum inertia requirement of the system under the constraint of the lowest frequency point is:

[0089]

[0090] in, The minimum inertia requirement of the system considering the frequency minimum point constraint in period t;

[0091] Taking all factors into consideration, the minimum inertia requirement of the system is:

[0092]

[0093] Among them, I sys,t,min is the minimum inertia requirement of the system in period t;

[0094] Calculate the frequency modulation and inertia shortage of the system in each period;

[0095] System primary frequency regulation shortage:

[0096]

[0097] in, It is the frequency regulation shortage of the system in period t;

[0098] System inertia deficit:

[0099] I sys,t,vac =I sys,t,min -I 1,t t=1,…,T

[0100] Among them, I sys,t,vac is the inertia shortage of the system in period t.

[0101] As a preferred solution of the method for sequentially acquiring the multi-resource inertia and primary frequency regulation auxiliary services of the present invention, the method for optimizing the acquisition of the grid-forming energy storage inertia and primary frequency regulation auxiliary services comprises the following steps:

[0102] Calculate the system frequency deviation change during the period when the system primary frequency regulation deficit is greater than 0 after the conventional units, energy storage and new energy in operation obtained in step 1 provide primary frequency regulation;

[0103]

[0104] Where Δf 1,t Provide the system frequency deviation after one frequency modulation for the system operating units obtained in step 1 during period t;

[0105] Calculate the frequency deviation as Δf 1,t After the disturbance, the total primary frequency regulation capacity that the grid-connected energy storage on standby in each period can provide;

[0106] The frequency deviation is Δf 1,t When there is a disturbance, the primary frequency regulation capacity that a single grid-connected energy storage can provide is:

[0107]

[0108] in, The frequency deviation is Δf 1,t When there is a disturbance, the primary frequency regulation capacity provided by the grid-type energy storage i;

[0109] Then, the frequency deviation is Δf 1,t When there is a disturbance, the total primary frequency regulation capacity that the grid-connected energy storage on standby in each period can provide is:

[0110]

[0111] in, The frequency deviation is Δf 1,t When there is a disturbance, the total primary frequency regulation capacity that the grid-connected energy storage on standby during period t can provide; is the grid-connected energy storage set that is on standby during period t;

[0112] Calculate the total inertia that can be provided by the grid-connected energy storage in standby mode in each period;

[0113]

[0114] Among them, I s2,t The total inertia that can be provided by the grid-connected energy storage on standby during period t;

[0115] Obtain the inertia and primary frequency regulation auxiliary service deficit;

[0116] To obtain the inertia and primary frequency regulation auxiliary service deficit, there are the following situations:

[0117] Ⅰ. If This indicates that the primary frequency regulation capacity provided by the grid-type energy storage on standby during period t of the system can already meet the shortage demand, and only the primary frequency regulation auxiliary service needs to be obtained from the grid-type energy storage on standby;

[0118] II. If This indicates that the primary frequency regulation capacity provided by the grid-type energy storage in the system during period t cannot meet the shortage demand; it is necessary to obtain primary frequency regulation auxiliary services from the remaining conventional units, i.e., step 5;

[0119] III. If I s2,t ≥I sys,t,vac , indicating that the inertia provided by the grid-type energy storage in the system during period t can already meet the shortage demand, and it is only necessary to obtain inertia auxiliary services from the grid-type energy storage in the system;

[0120] IV. If I s2,t <I sys,t,vac , indicating that the inertia provided by the grid-type energy storage in the system during period t cannot meet the shortage demand, and it is necessary to obtain inertia auxiliary services from the remaining conventional units, that is, step 5;

[0121] Obtain the objective function of inertia and primary frequency regulation auxiliary service deficit:

[0122]

[0123] in, is the virtual inertia quotation of grid-type energy storage i, RMB / (MWs); The price of primary frequency regulation of grid-type energy storage i, RMB / MW;

[0124] For the above cases I and III, the constraints are:

[0125] (1) Primary frequency regulation demand constraints:

[0126]

[0127] (2) Inertia requirement constraint:

[0128]

[0129] (3) Energy storage charging and discharging power constraints:

[0130]

[0131] (4) Energy storage charge state constraints:

[0132]

[0133] The virtual inertia and primary frequency regulation clearing prices are sorted from low to high by the virtual inertia and primary frequency regulation prices declared by the energy storage, and marginal inertia and primary frequency regulation service providers are found. The inertia and primary frequency regulation services for this period are priced according to the marginal energy storage inertia and primary frequency regulation prices.

[0134] As a preferred solution of the method for sequentially acquiring the inertia of multiple resources and the primary frequency regulation auxiliary service of the present invention, wherein: the optimization acquisition of the inertia and the primary frequency regulation auxiliary service of the conventional unit is performed; comprising the following steps:

[0135] Conventional units can provide corresponding rotational inertia and primary frequency regulation by operating at minimum power output. Therefore, the minimum output cost generated by conventional units in a certain period of time is the cost required to provide the units with rotational inertia and primary frequency regulation.

[0136] Construct an optimization acquisition model for the inertia of conventional units and primary frequency regulation auxiliary services;

[0137] Objective function:

[0138]

[0139] Among them, Ω g2,t is the set of remaining conventional units in period t; ρ g,i,min is the minimum power quotation of conventional unit i;

[0140] For cases II and IV in step 4, the constraints are:

[0141] (1) Primary frequency regulation demand constraints:

[0142]

[0143] (2) Inertia requirement constraint:

[0144]

[0145] (3) Start-up and shutdown time constraints of remaining conventional units:

[0146]

[0147] As a preferred solution of the method for sequentially acquiring the multi-resource inertia and primary frequency regulation auxiliary services of the present invention, the method is based on carrying out formal clearing of the multi-subject day-ahead electric energy market, and in the determined startup, performing day-ahead electric energy market clearing optimization calculation, including the following steps:

[0148] Construct a formal clearing model of the day-ahead spot market for multiple entities;

[0149] Objective function:

[0150]

[0151] Constraints:

[0152] (1) System load power balance constraints:

[0153]

[0154] Among them, Ω g3,t is the number of normal units started in step 5 during period t;

[0155] (2) System spare capacity constraints:

[0156]

[0157] (3) Network security constraints:

[0158]

[0159] (4) Output constraints of conventional units:

[0160]

[0161] (5) Conventional unit climbing constraints:

[0162]

[0163] (6) Output constraints of new energy units:

[0164]

[0165] (7) Energy storage charging and discharging power constraints:

[0166]

[0167] in, is the energy storage set obtained in step 4 during period t; (8) Energy storage charge state constraint:

[0168]

[0169] Among them about The expression is as follows:

[0170]

[0171] The electricity clearing price provides the electricity quotation of marginal electricity generating units in each period;

[0172] (1) Day-ahead market revenue of conventional units:

[0173] Electricity cost:

[0174]

[0175] in, is the daily energy cost of conventional unit i in the electricity market; is the electricity clearing price during period t;

[0176] Conventional unit inertia and primary frequency regulation auxiliary service fees:

[0177]

[0178] in, is the daily inertia of conventional unit i and the primary frequency regulation auxiliary service fee;

[0179] (2) Day-ahead market revenue of energy storage:

[0180] Energy storage power benefits:

[0181]

[0182] in, The daily energy cost of storing energy i for the electricity market;

[0183] Grid energy storage inertia and primary frequency regulation auxiliary service fees:

[0184]

[0185] in, The daily inertia of market energy storage i and the primary frequency regulation ancillary service fee; is the virtual inertia clearing price of energy storage in period t; The frequency regulation clearing price of energy storage in period t;

[0186] (3) Day-ahead market revenue of grid-connected new energy:

[0187] Grid-building new energy inertia and primary frequency regulation auxiliary service fees:

[0188]

[0189] in, Daily inertia and primary frequency regulation auxiliary service fees for market-based new energy i;

[0190] (4) Settlement model and cost sharing:

[0191] The settlement model adopts a daily settlement and monthly settlement method. The executed transaction results are cleared and calculated every day, and the settlement basis is issued and the fee settlement is carried out on a natural month basis; fee sharing: the electricity fee and the inertia and primary frequency regulation auxiliary service fees are shared by users according to their respective electricity consumption ratios.

[0192] In a second aspect, an embodiment of the present invention provides a system for sequentially acquiring multi-resource inertia and primary frequency modulation auxiliary services, which includes:

[0193] The pre-processing module conducts pre-clearing of the day-ahead electricity energy market for multiple entities;

[0194] Verification module, performs system frequency safety verification. If the frequency safety requirements are met, it proceeds to the final step; if not, it proceeds to the next step;

[0195] The calculation module calculates the inertia and primary frequency regulation shortfall required for system frequency safety during the period when frequency safety is not met;

[0196] The optimization module optimizes the acquisition of grid-type energy storage inertia and primary frequency regulation auxiliary services; if the acquired inertia and primary frequency regulation meet the shortfall, it proceeds to the final step; if not, it proceeds to the next step;

[0197] Acquisition module, which optimizes the acquisition of inertia of conventional units and primary frequency regulation auxiliary services;

[0198] The calculation module carries out the formal clearing of the day-ahead electricity energy market for multiple entities and performs the optimization calculation of the day-ahead electricity energy market clearing under the determined startup mode.

[0199] In a third aspect, an embodiment of the present invention provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, wherein: when the computer program instructions are executed by the processor, the steps of the method for sequentially acquiring multi-resource inertia and primary frequency modulation auxiliary services as described in the first aspect of the present invention are implemented.

[0200] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program instructions are executed by a processor, the steps of the method for sequentially acquiring multi-resource inertia and primary frequency modulation auxiliary services as described in the first aspect of the present invention are implemented.

[0201] The beneficial effects of the present invention are as follows: the present invention carries out pre-clearing of the day-ahead electric energy market of multiple entities; performs system frequency safety verification; calculates the inertia and primary frequency regulation shortage required for system frequency safety for the period when frequency safety is not met; optimizes the acquisition of grid-type energy storage inertia and primary frequency regulation auxiliary services; optimizes the acquisition of inertia and primary frequency regulation auxiliary services of conventional units; carries out formal clearing of the day-ahead electric energy market of multiple entities, and performs optimization calculation of day-ahead electric energy market clearing under a determined startup mode. The present invention takes into account the system frequency safety verification and the calculation of system inertia and primary frequency regulation demand shortage, realizes the optimized acquisition of inertia of multiple entities and primary frequency regulation auxiliary services, and provides guarantee for the safe and stable operation of the power system.

[0202] The present invention performs system frequency security verification on the basis of multi-subject electric energy market pre-clearing, calculates inertia and primary frequency regulation shortfall for periods when system frequency security is not satisfied, and coordinates synchronous generator sets, energy storage, new energy and other entities to provide inertia and primary frequency regulation services in order to obtain the inertia and primary frequency regulation shortfall. BRIEF DESCRIPTION OF THE DRAWINGS

[0203] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0204] Figure 1 A flow chart of a method for sequentially acquiring multiple resource inertia and primary frequency regulation auxiliary services;

[0205] Figure 2 Computer equipment diagram for sequential acquisition method of multi-resource inertia and primary frequency regulation auxiliary services. DETAILED DESCRIPTION

[0206] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0207] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0208] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0209] Example 1

[0210] Reference Figure 1-2 , which is the first embodiment of the present invention, and provides a method for sequentially acquiring multi-resource inertia and primary frequency modulation auxiliary services, including:

[0211] S100: Carry out pre-clearing of the day-ahead electricity energy market by multiple entities;

[0212] S101: Based on the pre-clearing of the day-ahead electricity energy market by multiple entities, including energy storage and new energy, there are both grid-following and grid-building types;

[0213] The virtual inertia and inertia support power provided by the grid-type energy storage are shown in the following formulas:

[0214]

[0215] in, are the virtual inertia of the grid-type energy storage i in charging and discharging states, MWs; It is a grid-type energy storage collection; is the inertia time constant of the grid-type energy storage i, s; They are the maximum charging and discharging power of grid-type energy storage i respectively; are the inertia support power of the grid-type energy storage i in charging and discharging states; RoCoF max It is the maximum frequency change limit allowed after the system is disturbed; f0 is the rated frequency of the system;

[0216] The virtual inertia and inertia support power provided by the network-building new energy are shown in the following formulas:

[0217]

[0218] Among them, I ne,i is the virtual inertia of the grid-connected new energy unit i, MWs; is the inertia time constant of the grid-connected new energy unit i, s; P ne,i,max is the rated power of the grid-connected new energy unit i; To build a network of new energy units; To build the inertia support power of the new energy i of the grid;

[0219] Construct a multi-subject day-ahead market pre-clearing model;

[0220] Objective function:

[0221]

[0222] Where T is the total number of time periods, 24 or 96; N g is the total number of conventional units; is the grid-connected energy storage set; M is the total number of conventional unit quotation segments; ρ i,m The power quotation for the mth section of conventional unit i; are the charging and discharging quotations of energy storage i respectively; P i,m,t is the active power of the mth section of the conventional unit i in time period t; are the charging and discharging power of energy storage i in time period t; u i,t is the start-stop state variable of conventional unit i in period t, u i,t =1 means power on, ui,t =0 means shutdown; is the startup cost of conventional unit i;

[0223] Constraints:

[0224] (1) System load power balance constraints:

[0225]

[0226] in, For the grid-based new energy collection; P g,i,t is the active power of conventional unit i in period t; P ne,i,t is the active power of the new energy unit i in period t; P load,t is the system active load during period t;

[0227] (2) System spare capacity constraints:

[0228]

[0229] Among them, P g,i,max , P g,i,min are the maximum and minimum active power of conventional unit i respectively; R t,up , R t,dn are the upper and lower reserve capacity requirements of the system in period t respectively;

[0230] (3) Network security constraints:

[0231]

[0232] Among them, N bus is the number of system nodes; N b is the number of lines; P l,max is the active power transmission limit of line l; G j,l is the power transfer factor of node j to line l; P g,j,t , P ne,j,t are respectively the active power of the conventional unit and the new energy unit at node j in period t; are the energy storage charging and discharging power at node j during period t; P load,j,t is the active load on node j during period t;

[0233] (4) Output constraints of conventional units:

[0234] u i,t P g,i,min ≤P g,i,t ≤u i,t P g,i,max i=1,2,…,N g ; t=1,2,…,T

[0235] (5) Conventional unit climbing constraints:

[0236]

[0237] Where ΔP i,dn , ΔP i,up are the maximum downward and upward climbing amounts of conventional unit i in a single period, respectively;

[0238] (6) Minimum continuous start and stop time constraints for conventional units:

[0239]

[0240] Among them, T i,t,up 、T i,t,dn are the continuous start and stop times of conventional unit i in period t; T i,up 、T i,dn are the minimum start and stop time requirements of conventional unit i respectively;

[0241] (7) Output constraints of new energy units:

[0242]

[0243] in, is the active power prediction of new energy unit i in period t; Reserve capacity for primary frequency regulation of grid-connected renewable energy i, MW;

[0244] (8) Energy storage charging and discharging power constraints:

[0245]

[0246] in, are 0-1 variables representing the charge and discharge states of energy storage i in period t, Indicates that it is in charging state. Indicates that it is in the discharge state; Reserve capacity for primary frequency regulation of grid-type energy storage i;

[0247] (9) Energy storage charge state constraints:

[0248]

[0249] Among them, S s,i,t B is the state of charge of energy storage i in period t; s,i is the rated capacity of energy storage i; are the charging and discharging efficiencies of energy storage i; Δt is a time interval; S s,i,min , S s,i,maxare the minimum and maximum capacities of energy storage i under stable operation, respectively; is the reserved energy of grid-type energy storage i in period t; S s,i,0 , S s,i,T are the initial and final values ​​of the state of charge of energy storage i respectively; The expression is as follows:

[0250]

[0251] in, and They are the energy required to be reserved for inertia and primary frequency regulation services provided by the grid-connected energy storage i during period t; T s,ramp It is the complete response time of primary frequency regulation of grid-type energy storage.

[0252] S200: Perform system frequency safety check. If the frequency safety requirements are met, enter S600. If not, enter S300.

[0253] S201: Based on the system frequency safety check, if the frequency safety requirements are met, proceed to the final step, if not, proceed to the next step; the check steps are as follows:

[0254] S202: Define the power shortage of the power shortage type fault in each time period as P loss,t =λP load,t , λ is the power disturbance ratio; the maximum frequency deviation allowed by the system when a disturbance occurs is specified as Δf max ;

[0255] S203: Calculate the maximum sum of primary frequency regulation capacity and the sum of inertia that can be provided by conventional units, energy storage and new energy in each period obtained in S100. Here, S100 represents the pre-clearing of the day-ahead electricity energy market for multiple entities.

[0256] (1) When the frequency deviation is Δf max During disturbance, the primary frequency regulation capacity provided by a single conventional unit is as follows:

[0257]

[0258] in, The frequency deviation is Δf max During disturbance, the primary frequency regulation capacity provided by conventional unit i; K g,i is the droop coefficient of conventional unit i, MW / Hz; Reserve capacity for primary frequency regulation of conventional unit i;

[0259] When the frequency deviation is Δf maxWhen there is a disturbance, the primary frequency regulation capacity that a single grid-connected energy storage can provide is:

[0260]

[0261] in, The frequency deviation is Δf max When there is a disturbance, the primary frequency regulation capacity provided by the grid-type energy storage i; K s,i is the virtual droop coefficient of the grid-type energy storage i, MW / Hz;

[0262] When the frequency deviation is Δf max When there is a disturbance, the primary frequency regulation capacity that a single grid-connected new energy unit can provide is:

[0263]

[0264] in, The frequency deviation is Δf max When there is a disturbance, the primary frequency regulation capacity provided by the grid-connected renewable energy source i; K ne,i is the virtual droop coefficient of the grid-connected new energy unit i, MW / Hz;

[0265] Then, the conventional units, energy storage and new energy units in each period obtained in S100 have a frequency deviation of Δf max During a disturbance, the maximum total primary frequency modulation capacity that can be provided in each period is:

[0266]

[0267] in, The frequency deviation during period t is Δf max When there is a disturbance, the total primary frequency modulation capacity that the system can provide is obtained from S100; Ω g1,t , They are respectively the sets of conventional units, grid-connected energy storage units, and grid-connected new energy units started up by S100 in period t;

[0268] (2) According to the system operation status obtained by S100, the total inertia of the system in each period is:

[0269]

[0270] Among them, I 1,t for t The sum of system inertia obtained by S100 during the period; is the inertia time constant of conventional unit i, s;

[0271] S203: I 1,tSubstitute it into the three major frequency safety constraints for verification; the three major constraints are frequency change rate constraint, frequency minimum point constraint, and quasi-steady-state frequency constraint;

[0272] The three frequency safety constraints are as follows:

[0273] (1) Frequency change rate constraint:

[0274]

[0275] Among them, I sys,t is the inertia of the system in period t;

[0276] (2) Frequency minimum point constraint:

[0277]

[0278] in, is the primary frequency regulation capacity of the system in period t; T g,ramp T is the complete response time of a conventional unit frequency modulation, which generally takes 10 to 20 seconds; del It is the primary frequency regulation response delay of conventional units, which is generally less than 3s;

[0279] (3) Quasi-steady-state frequency constraint:

[0280]

[0281] Specific verification method: Substitution I 1,t Substitute I sys,t If all three constraints are met, the system meets the frequency safety requirements in all time periods; if one of the constraints is not met, it indicates that the system inertia and primary frequency regulation capacity in time period t are insufficient, and it is necessary to obtain inertia and primary frequency regulation auxiliary services.

[0282] S300: Calculate the inertia and primary frequency regulation shortfall required for system frequency safety during the period when frequency safety is not met;

[0283] S301: Calculate the inertia and primary frequency regulation shortfall required for system frequency safety based on the period in which frequency safety is not satisfied; including the following processes:

[0284] Calculate the system's minimum primary frequency modulation requirement and inertia requirement;

[0285] After a large disturbance occurs, the system frequency needs to return to a quasi-steady state, so at least the quasi-steady state constraint must be met. Then the minimum frequency modulation capacity requirement of the system is:

[0286]

[0287] The minimum inertia requirement of the system is calculated based on the frequency change rate constraint:

[0288]

[0289] in, The minimum inertia requirement of the system considering the frequency change rate constraint in period t;

[0290] According to the frequency minimum point constraint, when Taking the minimum value, the right side of the formula has the maximum value, so the minimum inertia requirement of the system under the constraint of the lowest frequency point is:

[0291]

[0292] in, The minimum inertia requirement of the system considering the frequency minimum point constraint in period t;

[0293] Taking all factors into consideration, the minimum inertia requirement of the system is:

[0294]

[0295] Among them, I sys,t,min is the minimum inertia requirement of the system in period t;

[0296] S302: Calculate the frequency modulation and inertia shortage of the system in each period;

[0297] System primary frequency regulation shortage:

[0298]

[0299] in, It is the frequency regulation shortage of the system in period t;

[0300] System inertia deficit:

[0301] I sys,t,vac =I sys,t,min -I 1,t t=1,…,T

[0302] Among them, I sys,t,vac is the inertia shortage of the system in period t.

[0303] S400: Optimize and obtain the grid-type energy storage inertia and primary frequency regulation auxiliary services. If the acquired inertia and primary frequency regulation meet the shortage, enter S600; if not, enter S500;

[0304] S401: Based on optimizing the acquisition of grid-type energy storage inertia and primary frequency regulation auxiliary services, the following steps are included;

[0305] Calculate the system frequency deviation change during the period when the primary frequency regulation shortage is greater than 0 after the primary frequency regulation provided by the conventional units, energy storage and new energy in operation obtained in S100;

[0306]

[0307] Where Δf 1,t Provide the system frequency deviation after one frequency modulation for the system operating units obtained in S100 during period t;

[0308] S402: Calculate the frequency deviation as Δf 1,t After the disturbance, the total primary frequency regulation capacity that the grid-connected energy storage on standby in each period can provide;

[0309] The frequency deviation is Δf 1,t When there is a disturbance, the primary frequency regulation capacity that a single grid-connected energy storage can provide is:

[0310]

[0311] in, The frequency deviation is Δf 1,t When there is a disturbance, the primary frequency regulation capacity provided by the grid-type energy storage i;

[0312] Then, the frequency deviation is Δf 1,t When there is a disturbance, the total primary frequency regulation capacity that the grid-connected energy storage on standby in each period can provide is:

[0313]

[0314] in, The frequency deviation is Δf 1,t When there is a disturbance, the total primary frequency regulation capacity that the grid-connected energy storage on standby during period t can provide; It is a grid-connected energy storage collection that is on standby during period t.

[0315] S403: Calculating the total inertia that can be provided by the grid-connecting energy storage in standby mode in each time period;

[0316]

[0317] Among them, I s2,t It is the total inertia that the grid-connected energy storage can provide when on standby during period t.

[0318] S404: Acquiring inertia and primary frequency regulation auxiliary service shortage;

[0319] To obtain the inertia and primary frequency regulation auxiliary service deficit, there are the following situations:

[0320] Ⅰ. If This indicates that the primary frequency regulation capacity provided by the grid-type energy storage on standby during period t of the system can already meet the shortage demand, and only the primary frequency regulation auxiliary service needs to be obtained from the grid-type energy storage on standby;

[0321] II. If This indicates that the primary frequency regulation capacity provided by the grid-type energy storage in the system during period t cannot meet the shortage demand; it is necessary to obtain primary frequency regulation auxiliary services from the remaining conventional units, namely S500;

[0322] III. If I s2,t ≥I sys,t,vac , indicating that the inertia provided by the grid-type energy storage in the system during period t can already meet the shortage demand, and it is only necessary to obtain inertia auxiliary services from the grid-type energy storage in the system;

[0323] IV. If I s2,t <I sys,t,vac , indicating that the inertia provided by the grid-type energy storage in the system during period t cannot meet the shortage demand, and it is necessary to obtain inertia auxiliary services from the remaining conventional units, that is, S500;

[0324] Obtain the objective function of inertia and primary frequency regulation auxiliary service deficit:

[0325]

[0326] in, is the virtual inertia quotation of grid-type energy storage i, RMB / (MWs); The price of primary frequency regulation of grid-type energy storage i, RMB / MW;

[0327] For the above cases I and III, the constraints are:

[0328] (1) Primary frequency regulation demand constraints:

[0329]

[0330] (2) Inertia requirement constraint:

[0331]

[0332] (3) Energy storage charging and discharging power constraints:

[0333]

[0334] (4) Energy storage charge state constraints:

[0335]

[0336] The virtual inertia and primary frequency regulation clearing prices are sorted from low to high by the virtual inertia and primary frequency regulation prices declared by the energy storage, and marginal inertia and primary frequency regulation service providers are found. The inertia and primary frequency regulation services for this period are priced according to the marginal energy storage inertia and primary frequency regulation prices.

[0337] S500: Optimize the inertia of conventional units and primary frequency regulation auxiliary services;

[0338] S501: Based on the optimization acquisition of the inertia of the conventional unit and the primary frequency regulation auxiliary service; comprising the following steps:

[0339] Conventional units can provide corresponding rotational inertia and primary frequency regulation by operating at minimum power output. Therefore, the minimum output cost generated by conventional units in a certain period of time is the cost required to provide the units with rotational inertia and primary frequency regulation.

[0340] Construct an optimization acquisition model for the inertia of conventional units and primary frequency regulation auxiliary services;

[0341] Objective function:

[0342]

[0343] Among them, Ω g2,t is the set of remaining conventional units in period t; ρ g,i,min is the minimum power quotation of conventional unit i;

[0344] For the second and fourth cases in S404, the constraints are:

[0345] (1) Primary frequency regulation demand constraints:

[0346]

[0347] (2) Inertia requirement constraint:

[0348]

[0349] (3) Start-up and shutdown time constraints of remaining conventional units:

[0350]

[0351] S600: Carry out the formal clearing of the day-ahead electricity energy market of multiple entities, and perform the optimization calculation of the day-ahead electricity energy market clearing under the determined startup mode.

[0352] S601: Based on the formal clearing of the multi-subject day-ahead electric energy market, the day-ahead electric energy market clearing optimization calculation is performed among the determined operators, including the following steps:

[0353] Construct a formal clearing model of the day-ahead spot market for multiple entities;

[0354] Objective function:

[0355]

[0356] Constraints:

[0357] (1) System load power balance constraints:

[0358]

[0359] Among them, Ω g3,t is the number of normal units started in period S500; (2) System reserve capacity constraint:

[0360]

[0361] (3) Network security constraints:

[0362]

[0363] (4) Output constraints of conventional units:

[0364]

[0365] (5) Conventional unit climbing constraints:

[0366]

[0367] (6) Output constraints of new energy units:

[0368]

[0369] (7) Energy storage charging and discharging power constraints:

[0370]

[0371] in, is the energy storage set obtained in period S400;

[0372] (8) Energy storage charge state constraints:

[0373]

[0374] Among them about The expression is as follows:

[0375]

[0376] The electricity clearing price provides the electricity quotation of marginal electricity generating units in each period;

[0377] (1) Day-ahead market revenue of conventional units:

[0378] Electricity cost:

[0379]

[0380] in, is the daily energy cost of conventional unit i in the electricity market; is the electricity clearing price during period t;

[0381] Conventional unit inertia and primary frequency regulation auxiliary service fees:

[0382]

[0383] in, is the daily inertia of conventional unit i and the primary frequency regulation auxiliary service fee;

[0384] (2) Day-ahead market revenue of energy storage:

[0385] Energy storage power benefits:

[0386]

[0387] in, The daily energy cost of storing energy i for the electricity market;

[0388] Grid energy storage inertia and primary frequency regulation auxiliary service fees:

[0389]

[0390] in, The daily inertia of market energy storage i and the primary frequency regulation ancillary service fee; is the virtual inertia clearing price of energy storage in period t; The frequency regulation clearing price of energy storage in period t;

[0391] (3) Day-ahead market revenue of grid-connected new energy:

[0392] Grid-building new energy inertia and primary frequency regulation auxiliary service fees:

[0393]

[0394] in, Daily inertia and primary frequency regulation auxiliary service fees for market-based new energy i;

[0395] (4) Settlement model and cost sharing:

[0396] The settlement model adopts a daily settlement and monthly settlement method. The executed transaction results are cleared and calculated every day, and the settlement basis is issued and the fee settlement is carried out on a natural month basis; fee sharing: the electricity fee and the inertia and primary frequency regulation auxiliary service fees are shared by users according to their respective electricity consumption ratios.

[0397] Furthermore, this embodiment also provides a system for sequentially acquiring multiple resource inertia and primary frequency modulation auxiliary services, including:

[0398] The pre-processing module conducts pre-clearing of the day-ahead electricity energy market for multiple entities;

[0399] Verification module, performs system frequency safety verification. If the frequency safety requirements are met, it proceeds to the final step; if not, it proceeds to the next step;

[0400] The calculation module calculates the inertia and primary frequency regulation shortfall required for system frequency safety during the period when frequency safety is not met;

[0401] The optimization module optimizes the acquisition of grid-type energy storage inertia and primary frequency regulation auxiliary services; if the acquired inertia and primary frequency regulation meet the shortfall, it proceeds to the final step; if not, it proceeds to the next step;

[0402] Acquisition module, which optimizes the acquisition of inertia of conventional units and primary frequency regulation auxiliary services;

[0403] The calculation module carries out the formal clearing of the day-ahead electricity energy market for multiple entities and performs the optimization calculation of the day-ahead electricity energy market clearing under the determined startup mode.

[0404] This embodiment also provides a computer device, which is applicable to the method for sequentially acquiring multi-resource inertia and primary frequency modulation auxiliary services, and includes a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute computer-executable instructions to implement the method for sequentially acquiring multi-resource inertia and primary frequency modulation auxiliary services proposed in the above embodiment.

[0405] The computer device may be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0406] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the method for sequentially acquiring multi-resource inertia and primary frequency modulation auxiliary services proposed in the above embodiment is implemented.

[0407] In summary, the present invention conducts pre-clearing of the day-ahead electricity energy market for multiple entities; performs system frequency safety verification; calculates the inertia and primary frequency regulation shortfall required for system frequency safety for time periods when frequency safety is not met; optimizes the acquisition of grid-type energy storage inertia and primary frequency regulation auxiliary services; optimizes the acquisition of inertia and primary frequency regulation auxiliary services for conventional units; conducts formal clearing of the day-ahead electricity energy market for multiple entities, and performs optimization calculations for day-ahead electricity energy market clearing under a determined startup mode. The present invention takes into account system frequency safety verification and calculations of system inertia and primary frequency regulation demand shortfalls, realizes the optimized acquisition of inertia and primary frequency regulation auxiliary services for multiple entities, and provides guarantees for the safe and stable operation of the power system.

[0408] The present invention performs system frequency security verification on the basis of multi-subject electric energy market pre-clearing, calculates inertia and primary frequency regulation shortfall for periods when system frequency security is not satisfied, and coordinates synchronous generator sets, energy storage, new energy and other entities to provide inertia and primary frequency regulation services in order to obtain the inertia and primary frequency regulation shortfall.

[0409] Example 2

[0410] Reference Figure 1 - Figure 2 , which is the second embodiment of the present invention, and this embodiment provides a method for sequentially acquiring multi-resource inertia and primary frequency modulation auxiliary services. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

[0411] Take a typical regional power grid as an example. The installed capacity of the power grid is 15 million kilowatts, including 10 million kilowatts of thermal power units, 2 million kilowatts of hydropower, 1.5 million kilowatts of wind power, 1 million kilowatts of photovoltaic power, and 500,000 kilowatts of energy storage. A typical summer high-load day is selected as the simulation day, and the system peak load is 10 million kilowatts. The inertia time constant of the thermal power unit is 5s, the droop coefficient is 2%, and the minimum technical output is set to 50%. Wind power and photovoltaic power do not provide inertia, and the output is given according to typical day data. The virtual inertia time constant of the grid energy storage is 1s, the virtual droop coefficient is 16%, the maximum charge and discharge capacity is 250,000 kilowatts, the conversion efficiency is 90%, and the initial and final values ​​of SOC are set to 60%.

[0412] In order to optimize the operation cost of the power grid, the conventional day-ahead electricity energy market is first cleared, and then the system frequency safety check is performed. Assume that from 10:00 to 11:00 a.m. and from 2:00 to 3:00 p.m., the check process finds that the system inertia and primary frequency regulation capacity do not meet the requirements. Using the method of the present invention, it is calculated that the primary frequency regulation shortage is 300,000 kilowatts and the inertia shortage is 800MW·s from 10:00 to 11:00 a.m., and the primary frequency regulation shortage is 200,000 kilowatts and the inertia shortage is 300MW·s from 2:00 to 3:00 p.m. According to the results, the optimization acquisition of inertia and primary frequency regulation auxiliary services is carried out respectively.

[0413] At 10 am, the grid energy storage auxiliary service is first obtained. Assuming that the available grid energy storage capacity is 400,000 kilowatts, the virtual inertia quotation is 20 yuan and MW·s, and the primary frequency regulation quotation is 50 yuan and MW. The optimization result is to obtain 800MW·s of virtual inertia of grid energy storage and 300,000 kilowatts of primary frequency regulation, which just meets the system demand. According to marginal pricing, the prices of virtual inertia and primary frequency regulation auxiliary services are 20 yuan and MW·s and 50 yuan and MW respectively. At this time, there is no need to obtain auxiliary services for thermal power units.

[0414] At 2 pm, the grid energy storage auxiliary service is also obtained first. Due to the high photovoltaic output, it is assumed that only 100,000 kW of grid energy storage is available at this time, and the primary frequency regulation quotation is 80 yuan and MW. The optimization results show that the grid energy storage cannot meet the system inertia requirements, and only 100,000 kW of grid energy storage is obtained for primary frequency regulation. In order to meet the 300MW·s inertia requirement, inertia services must also be obtained from thermal power units. Through optimization, the G1 thermal power unit is started to provide auxiliary services, operating at its minimum technical output, providing an inertia of 300MW·s and a primary frequency regulation of 100,000 kW. According to marginal pricing, the price of the primary frequency regulation auxiliary service is the minimum electricity quotation of the thermal power G1.

[0415] While obtaining ancillary services, a revised thermal power startup combination was obtained, based on which the day-ahead power energy market was formally cleared again. The results obtained were released to all market players together with the ancillary service results. The day-ahead market revenue of each type of resource includes power energy revenue and inertia and primary frequency regulation ancillary service revenue.

[0416] In order to verify the economy and effectiveness of the method proposed in the present invention, the following three schemes are designed for comparison:

[0417] Option 1: Traditional electricity market without considering system frequency constraints;

[0418] Option 2: Based on the electric energy market, obtain the inertia and primary frequency regulation auxiliary services of thermal power units;

[0419] Solution 3: The solution of the present invention coordinates multiple types of resources to provide electric energy, inertia and primary frequency regulation services.

[0420] The comparison of the optimization results of the three schemes during peak hours is shown in Table 1.

[0421] Table 1 Comparison of optimization results during peak hours

[0422] index Solution 1 Solution 2 Solution 3 Thermal power generation capacity (MW) 7500 8200 8000 System primary frequency modulation (MW) 500 730 720 System inertia (MW·s) 37500 41000 40800 Grid energy storage inertia (MW·s) 0 0 800 Grid energy storage frequency regulation (MW) 0 0 300 Market cost today (10,000 yuan) 1925.6 2120.4 2029.7

[0423] As can be seen from Table 1, Scheme 1 has the lowest operating cost, but due to the lack of sufficient inertia and frequency regulation resources, the system is not flexible enough and it is difficult to cope with large disturbances. Both Schemes 2 and 3 can provide sufficient inertia and primary frequency regulation capacity, but due to the coordinated configuration of multiple different types of resources, Scheme 3 has a lower operating cost than Scheme 2.

[0424] Assuming that the rated frequency of the system is 50Hz, due to a -5% load disturbance occurring from 10:00 to 11:00 and from 14:00 to 15:00, the dynamic response of the frequency deviation is as follows:

[0425] In Scheme 1, due to insufficient inertia and frequency modulation, the frequency dropped sharply, with the maximum deviation reaching -0.35Hz, exceeding the allowable lower limit of -0.2Hz, and the frequency drop lasted for more than 1 minute. The frequency modulation process was slow, and it took more than 5 minutes for the frequency to recover to the rated value of 50Hz.

[0426] Both Scheme 2 and Scheme 3 can control the frequency drop to within 0.2 Hz within 1 second, and can restore the frequency to near the rated value in about 30 seconds. The entire frequency modulation process takes less than 1 minute.

[0427] Further comparison of Schemes 2 and 3 shows that the maximum frequency drop in Scheme 3 is about -0.18Hz, which is less than -0.195Hz in Scheme 2. This is because the virtual inertia of the energy storage in Scheme 3 can respond within the ms time scale, suppressing the sharp drop in frequency at the first time. At the same time, due to the fast frequency modulation characteristics of energy storage, the frequency fluctuation in the frequency modulation process of Scheme 3 is also significantly smaller than that of Scheme 2, which is conducive to reducing the dynamic loss of the system.

[0428] It can be seen that the system frequency deviation of Scheme 1 exceeds the allowable range of ±0.2Hz, and the frequency modulation process is slow. While both Schemes 2 and 3 can quickly control the frequency deviation within the allowable range, but Scheme 3 has smaller frequency fluctuations and lower system losses due to the rapid response of energy storage.

[0429] In summary, the multi-resource inertia and primary frequency modulation auxiliary service sequential acquisition method proposed in the present invention effectively reduces the operating cost while ensuring the system frequency safety, and improves the dynamic response performance of the system. Compared with the prior art, it is mainly reflected in the following innovations:

[0430] Based on the introduction of inertia and primary frequency regulation auxiliary service markets in the electric energy market, a diversified power auxiliary service supply mechanism is formed, which provides important support for the safe and economical operation of the power grid with high penetration of new energy.

[0431] 2. The physical characteristics of different types of resources are fully considered, and modeling methods for different resources are proposed. Synchronous machines, energy storage and new energy participate in inertia and primary frequency regulation response through different virtual inertia and virtual droop coefficients.

[0432] 3. In accordance with the principle of "energy storage first, conventional units as supplement", the optimization of ancillary services for grid-connected energy storage and conventional units is carried out in sequence, which effectively reduces the operating and ancillary service costs while meeting the system flexibility requirements.

[0433] 4. Finally, the startup mode of the electricity energy market was revised to achieve the coordinated optimization of electricity energy and ancillary services. Various market players can also obtain benefits from multiple services at the same time, which is conducive to mobilizing their enthusiasm for participation.

[0434] Compared with the existing method of obtaining inertia frequency regulation services that only considers conventional units, the present invention innovatively incorporates resources such as configuration energy storage into a unified framework, making up for the shortcomings of existing methods. It will effectively promote the efficient and flexible operation of new power systems and is of great significance to innovating the power auxiliary service market mechanism and ensuring the safety and stability of the power grid.

[0435] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for sequentially acquiring multi-resource inertia and primary frequency modulation auxiliary services, characterized in that: Including carrying out pre-clearing of the day-ahead electricity energy market by multiple entities; Perform system frequency safety check. If the frequency safety requirements are met, proceed to the final step. If not, proceed to the next step. For the period when frequency safety is not met, calculate the inertia and primary frequency regulation shortfall required for system frequency safety; Optimize the acquisition of grid-type energy storage inertia and primary frequency regulation auxiliary services. If the acquired inertia and primary frequency regulation meet the shortfall, proceed to the final step. If not, proceed to the next step. Optimize the inertia of conventional units and primary frequency regulation auxiliary services; Carry out formal clearing of the day-ahead electricity energy market involving multiple entities, and perform optimization calculations for clearing the day-ahead electricity energy market under a determined startup method.

2. The method for sequentially acquiring multiple resource inertia and primary frequency modulation auxiliary services according to claim 1, characterized in that: The aforementioned is based on the pre-clearing of the day-ahead electricity energy market by multiple entities, including energy storage and new energy, which have both grid-following and grid-building types; The virtual inertia and inertia support power provided by the grid-type energy storage are shown in the following formulas: in, are the virtual inertia of the grid-type energy storage i in charging and discharging states, MWs; It is a grid-type energy storage collection; is the inertia time constant of the grid-type energy storage i, s; They are the maximum charging and discharging power of grid-type energy storage i respectively; are the inertia support power of the grid-type energy storage i in charging and discharging states; RoCoF max It is the maximum frequency change limit allowed after the system is disturbed; f0 is the rated frequency of the system; The virtual inertia and inertia support power provided by the network-building new energy are shown in the following formulas: Among them, I ne,i is the virtual inertia of the grid-connected new energy unit i, MWs; is the inertia time constant of the grid-connected new energy unit i, s; P ne,i,max is the rated power of the grid-connected new energy unit i; To build a collection of new energy units for grid-type construction; The inertia support power of the network-type new energy i; Construct a multi-subject day-ahead market pre-clearing model; Objective function: Where T is the total number of time periods, 24 or 96; N g is the total number of conventional units; is the grid-connected energy storage set; M is the total number of conventional unit quotation segments; ρ i,m The power quotation for the mth section of conventional unit i; are the charging and discharging quotations of energy storage i respectively; P i,m,t is the active power of the mth section of the conventional unit i in time period t; are the charging and discharging power of energy storage i in time period t; u i,t is the start-stop state variable of conventional unit i in period t, u i,t =1 means power on, u i,t =0 means shutdown; is the startup cost of conventional unit i; Constraints: (1) System load power balance constraints: in, For the grid-based new energy collection; P g,i,t is the active power of conventional unit i in period t; P ne,i,t is the active power of the new energy unit i in period t; P load,t is the system active load during period t; (2) System spare capacity constraints: Among them, P g,i,max , P g,i,min are the maximum and minimum active power of conventional unit i respectively; R t,up , R t,dn are the upper and lower reserve capacity requirements of the system in period t respectively; (3) Network security constraints: Among them, N bus is the number of system nodes; N b is the number of lines; P l,max is the active power transmission limit of line l; G j,l is the power transfer factor of node j to line l; P g,j,t , P ne,j,t are respectively the active power of the conventional unit and the new energy unit at node j in period t; are the energy storage charging and discharging power at node j during period t; P load,j,t is the active load on node j during period t; (4) Output constraints of conventional units: u i,t P g,i,min ≤P g,i,t ≤u i,t P g,i,max i=1,2,…,N g ;t=1,2,…,T (5) Conventional unit climbing constraints: Among them, ΔP i,dn , ΔP i,up are the maximum downward and upward climbing amounts of conventional unit i in a single period, respectively; (6) Minimum continuous start and stop time constraints for conventional units: Among them, T i,t,up 、T i,t,dn are the continuous start and stop times of conventional unit i in period t; T i,up 、T i,dn are the minimum start and stop time requirements of conventional unit i respectively; (7) Output constraints of new energy units: in, is the active power prediction of new energy unit i in period t; Reserve capacity for primary frequency regulation of grid-connected renewable energy i, MW; (8) Energy storage charging and discharging power constraints: in, are 0-1 variables representing the charge and discharge states of energy storage i in period t, Indicates that it is in charging state. Indicates that it is in the discharge state; Reserve capacity for primary frequency regulation of grid-type energy storage i; (9) Energy storage charge state constraints: Among them, S s,i,t B is the state of charge of energy storage i in period t; s,i is the rated capacity of energy storage i; are the charging and discharging efficiencies of energy storage i; Δt is a time interval; S s,i,min , S s,i,max are the minimum and maximum capacities of energy storage i under stable operation, respectively; is the reserved energy of grid-type energy storage i in period t; S s,i,0 , S s,i,T are the initial and final values ​​of the state of charge of energy storage i respectively; The expression is as follows: in, and They are the energy required to be reserved for inertia and primary frequency regulation services provided by the grid-connected energy storage i during period t; T s,ramp It is the complete response time of primary frequency regulation of grid-type energy storage.

3. The method for sequentially acquiring multiple resource inertia and primary frequency modulation auxiliary services according to claim 2, characterized in that: The system frequency safety check is performed based on the above. If the frequency safety requirements are met, the final step is entered. If not, the next step is entered. The check steps are as follows: The power shortage of power shortage type fault in each period is defined as P loss,t =λP load,t , λ is the power disturbance ratio; the maximum frequency deviation allowed by the system when a disturbance occurs is specified as Δf max ; Calculate the maximum sum of primary frequency regulation capacity and the sum of inertia that can be provided by conventional units, energy storage and new energy in each period obtained in step 1. Here, step 1 represents the pre-clearing of the multi-subject day-ahead electricity energy market; (1) When the frequency deviation is Δf max During disturbance, the primary frequency regulation capacity provided by a single conventional unit is as follows: in, The frequency deviation is Δf max During disturbance, the primary frequency regulation capacity provided by conventional unit i; K g,i is the droop coefficient of conventional unit i, MW / Hz; Reserve capacity for primary frequency regulation of conventional unit i; When the frequency deviation is Δf max When there is a disturbance, the primary frequency regulation capacity that a single grid-connected energy storage can provide is: in, The frequency deviation is Δf max When there is a disturbance, the primary frequency regulation capacity provided by the grid-type energy storage i; K s,i is the virtual droop coefficient of the grid-type energy storage i, MW / Hz; When the frequency deviation is Δf max When there is a disturbance, the primary frequency regulation capacity that a single grid-connected new energy unit can provide is: in, The frequency deviation is Δf max When there is a disturbance, the primary frequency regulation capacity provided by the grid-connected renewable energy source i; K ne,i is the virtual droop coefficient of the grid-connected new energy unit i, MW / Hz; Then, the conventional units, energy storage and new energy units in each period obtained in step 1 will have a frequency deviation of Δf max During a disturbance, the maximum total primary frequency modulation capacity that can be provided in each period is: in, The frequency deviation during period t is Δf max When there is a disturbance, the total primary frequency modulation capacity that the system can provide is obtained from step 1; Ω g1,t , are respectively the sets of conventional units, grid-connected energy storage units, and grid-connected new energy units started up in step 1 during time period t; (2) According to the system operation status obtained in step 1, the total inertia of the system in each period is: Among them, I 1,t for t The sum of the system inertia obtained in step 1 during the period; is the inertia time constant of conventional unit i, s; Will I 1,t Substitute it into the three major frequency safety constraints for verification; the three major constraints are frequency change rate constraint, frequency minimum point constraint, and quasi-steady-state frequency constraint; The three frequency safety constraints are as follows: (1) Frequency change rate constraint: Among them, I sys,t is the inertia of the system in period t; (2) Frequency minimum point constraint: in, is the primary frequency regulation capacity of the system in period t; T g,ramp T is the complete response time of a conventional unit frequency modulation, which generally takes 10 to 20 seconds; del It is the primary frequency regulation response delay of conventional units, which is generally less than 3s; (3) Quasi-steady-state frequency constraint: Specific verification method: Substitution I 1,t Substitute I sys,t If all three constraints are met, the system meets the frequency safety requirements in all time periods; if one of the constraints is not met, it indicates that the system inertia and primary frequency regulation capacity in time period t are insufficient, and it is necessary to obtain inertia and primary frequency regulation auxiliary services.

4. The method for sequentially acquiring multiple resource inertia and primary frequency modulation auxiliary services according to claim 3, characterized in that: The inertia and primary frequency regulation shortage required for system frequency safety are calculated based on the period in which frequency safety is not satisfied; The process includes: Calculate the system's minimum primary frequency modulation requirement and inertia requirement; After a large disturbance occurs, the system frequency needs to return to a quasi-steady state, so at least the quasi-steady state constraint must be met. Then the minimum frequency modulation capacity requirement of the system is: The minimum inertia requirement of the system is calculated based on the frequency change rate constraint: in, The minimum inertia requirement of the system considering the frequency change rate constraint in period t; According to the frequency minimum point constraint, when Taking the minimum value, the right side of the formula has the maximum value, so the minimum inertia requirement of the system under the constraint of the lowest frequency point is: in, The minimum inertia requirement of the system considering the frequency minimum point constraint in period t; Taking all factors into consideration, the minimum inertia requirement of the system is: Among them, I sys,t,min is the minimum inertia requirement of the system in period t; Calculate the frequency modulation and inertia shortage of the system in each period; System primary frequency regulation shortage: in, It is the frequency regulation shortage of the system in period t; System inertia deficit: I sys,t,vac =I sys,t,min -I 1,t t=1,…,T Among them, I sys,t,vac is the inertia shortage of the system in period t.

5. The method for sequentially acquiring multiple resource inertia and primary frequency modulation auxiliary services according to claim 4, characterized in that: The method of optimizing and acquiring the grid-connected energy storage inertia and primary frequency regulation auxiliary services comprises the following steps: Calculate the system frequency deviation change during the period when the system primary frequency regulation deficit is greater than 0 after the conventional units, energy storage and new energy in operation obtained in step 1 provide primary frequency regulation; Where Δf 1,t Provide the system frequency deviation after one frequency modulation for the system operating units obtained in step 1 during period t; Calculate the frequency deviation as Δf 1,t After the disturbance, the total primary frequency regulation capacity that the grid-connected energy storage on standby in each period can provide; The frequency deviation is Δf 1,t When there is a disturbance, the primary frequency regulation capacity that a single grid-connected energy storage can provide is: in, The frequency deviation is Δf 1,t When there is a disturbance, the primary frequency regulation capacity provided by the grid-type energy storage i; Then, the frequency deviation is Δf 1,t When there is a disturbance, the total primary frequency regulation capacity that the grid-connected energy storage on standby in each period can provide is: in, The frequency deviation is Δf 1,t When there is a disturbance, the total primary frequency regulation capacity that the grid-connected energy storage on standby during period t can provide; is the grid-connected energy storage set that is on standby during period t; Calculate the total inertia that can be provided by the grid-connected energy storage in standby mode in each period; Among them, I s2,t The total inertia that can be provided by the grid-connected energy storage on standby during period t; Obtain the inertia and primary frequency regulation auxiliary service deficit; To obtain the inertia and primary frequency regulation auxiliary service deficit, there are the following situations: Ⅰ. If This indicates that the primary frequency regulation capacity provided by the grid-type energy storage on standby during period t of the system can already meet the shortage demand, and only the primary frequency regulation auxiliary service needs to be obtained from the grid-type energy storage on standby; II. If This indicates that the primary frequency regulation capacity provided by the grid-type energy storage in the system during period t cannot meet the shortage demand; it is necessary to obtain primary frequency regulation auxiliary services from the remaining conventional units, i.e., step 5; III. If I s2,t ≥I sys,t,vac , indicating that the inertia provided by the grid-type energy storage in the system during period t can already meet the shortage demand, and it is only necessary to obtain inertia auxiliary services from the grid-type energy storage in the system; IV. If I s2,t <I sys,t,vac , indicating that the inertia provided by the grid-type energy storage in the system during period t cannot meet the shortage demand, and it is necessary to obtain inertia auxiliary services from the remaining conventional units, that is, step 5; Obtain the objective function of inertia and primary frequency regulation auxiliary service deficit: in, is the virtual inertia quotation of grid-type energy storage i, RMB / (MWs); The price of primary frequency regulation of grid-type energy storage i, RMB / MW; For the above cases I and III, the constraints are: (1) Primary frequency regulation demand constraints: (2) Inertia requirement constraint: (3) Energy storage charging and discharging power constraints: (4) Energy storage charge state constraints: The virtual inertia and primary frequency regulation clearing prices are sorted from low to high by the virtual inertia and primary frequency regulation prices declared by the energy storage, and marginal inertia and primary frequency regulation service providers are found. The inertia and primary frequency regulation services for this period are priced according to the marginal energy storage inertia and primary frequency regulation prices.

6. The method for sequentially acquiring multiple resource inertia and primary frequency modulation auxiliary services as claimed in claim 5, characterized in that: The optimization acquisition based on the inertia of conventional units and primary frequency regulation auxiliary services includes the following steps: Conventional units can provide corresponding rotational inertia and primary frequency regulation by operating at minimum power output. Therefore, the minimum output cost generated by conventional units in a certain period of time is the cost required to provide the units with rotational inertia and primary frequency regulation. Construct an optimization acquisition model for the inertia of conventional units and primary frequency regulation auxiliary services; Objective function: Among them, Ω g2,t is the set of remaining conventional units in period t; ρ g,i,min is the minimum power quotation of conventional unit i; For cases II and IV in step 4, the constraints are: (1) Primary frequency regulation demand constraints: (2) Inertia requirement constraint: (3) Start-up and shutdown time constraints of remaining conventional units:

7. The method for sequentially acquiring multiple resource inertia and primary frequency modulation auxiliary services according to claim 6, characterized in that: The method of performing the formal clearing of the day-ahead electric energy market by multiple entities and performing the day-ahead electric energy market clearing optimization calculation among the determined power generating parties comprises the following steps: Construct a formal clearing model of the day-ahead spot market for multiple entities; Objective function: Constraints: (1) System load power balance constraints: Among them, Ω g3,t is the number of normal units started in step 5 during period t; (2) System spare capacity constraints: (3) Network security constraints: (4) Output constraints of conventional units: (5) Conventional unit climbing constraints: (6) Output constraints of new energy units: (7) Energy storage charging and discharging power constraints: in, is the energy storage set obtained in step 4 during period t; (8) Energy storage charge state constraints: Among them about The expression is as follows: The electricity clearing price provides the electricity quotation of marginal electricity generating units in each period; (1) Day-ahead market revenue of conventional units: Electricity cost: in, is the daily energy cost of conventional unit i in the electricity market; is the electricity clearing price during period t; Conventional unit inertia and primary frequency regulation auxiliary service fees: in, is the daily inertia of conventional unit i and the primary frequency regulation auxiliary service fee; (2) Day-ahead market revenue of energy storage: Energy storage power benefits: in, The daily energy cost of storing energy i for the electricity market; Grid energy storage inertia and primary frequency regulation auxiliary service fees: in, The daily inertia of market energy storage i and the primary frequency regulation ancillary service fee; is the virtual inertia clearing price of energy storage in period t; The frequency regulation clearing price of energy storage in period t; (3) Day-ahead market revenue of grid-connected new energy: Grid-building new energy inertia and primary frequency regulation auxiliary service fees: in, Daily inertia and primary frequency regulation auxiliary service fees for market-based new energy i; (4) Settlement model and cost sharing: The settlement model adopts a daily settlement and monthly settlement method. The executed transaction results are cleared and calculated every day, and the settlement basis is issued and the fee settlement is carried out on a natural month basis; fee sharing: the electricity fee and the inertia and primary frequency regulation auxiliary service fees are shared by users according to their respective electricity consumption ratios.

8. A system for sequentially acquiring multiple resource inertia and primary frequency modulation auxiliary services, based on the method for sequentially acquiring multiple resource inertia and primary frequency modulation auxiliary services according to any one of claims 1 to 7, characterized in that: Also includes, The pre-processing module conducts pre-clearing of the day-ahead electricity energy market for multiple entities; Verification module, performs system frequency safety verification. If the frequency safety requirements are met, it proceeds to the final step; if not, it proceeds to the next step; The calculation module calculates the inertia and primary frequency regulation shortfall required for system frequency safety during the period when frequency safety is not met; The optimization module optimizes the acquisition of grid-type energy storage inertia and primary frequency regulation auxiliary services; if the acquired inertia and primary frequency regulation meet the shortfall, it proceeds to the final step; if not, it proceeds to the next step; Acquisition module, which optimizes the acquisition of inertia of conventional units and primary frequency regulation auxiliary services; The calculation module carries out the formal clearing of the day-ahead electricity energy market for multiple entities and performs the optimization calculation of the day-ahead electricity energy market clearing under the determined startup mode.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method for sequentially acquiring multi-resource inertia and primary frequency modulation auxiliary services described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for sequentially acquiring multi-resource inertia and primary frequency modulation auxiliary services described in any one of claims 1 to 7 are implemented.

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