Unit optimization method and system considering primary frequency modulation and stability control measures, and medium

Abstract

The invention discloses a unit optimization method and system considering primary frequency modulation and stability control measures and a medium. Relates to the technical field of power systems. Based on safe operation of a low-inertia power system, a unit combination optimization model capable of ensuring system frequency safety is provided, an objective function with the lowest total power generation cost as an objective is established, and a dynamic response principle of primary frequency modulation and system frequency of the system is combined. And deducing and establishing safety constraint conditions of the frequency change rate, the maximum frequency deviation and the quasi-steady-state frequency deviation, performing linearization processing on the safety constraint of the maximum frequency deviation in combination with a piecewise linearization technology, and solving the established model by using a CPLEX solver in combination with the constraint conditions of safe operation of the power system, so as to obtain the maximum frequency deviation. And a unit combination optimization scheme capable of ensuring the stable frequency of the power system is obtained, and validity verification is carried out on related constraints.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular to a method, system and medium for optimizing a unit taking primary frequency regulation and stabilization measures into consideration. Background Art

[0002] After wind power and other renewable energy generators are connected to the power grid, the system's rotational inertia level is greatly reduced, and the system's inertia support and frequency regulation capabilities under active disturbances are seriously reduced. The resulting frequency safety issues cause great economic losses to power grid operations. Adding safety constraints on frequency-related indicators to the unit combination optimization problem is an important way to solve this problem.

[0003] Regarding the problem of power grid unit combination optimization considering frequency safety constraints, the current power system's ability to maintain frequency stability mainly relies on synchronization units with slow dynamic frequency characteristics, and it is difficult to determine the lowest frequency point. There are inevitable errors in the linearization of the maximum frequency deviation safety constraint.

[0004] The traditional maximum frequency deviation safety constraint linearization method only considers the primary frequency regulation effect of the generator set. However, when major faults such as large-capacity unit tripping and DC interlocking occur in the system, it cannot guarantee the safe and stable operation of the power system, and the frequency safety problem cannot be effectively solved. Summary of the invention

[0005] The technical problem to be solved by the present invention is that the traditional maximum frequency deviation safety constraint linearization method only considers the primary frequency regulation effect of the generator set, and cannot ensure the safe and stable operation of the power system when major faults such as large-capacity unit tripping and DC interlocking occur in the system, and the frequency safety problem cannot be effectively solved. The purpose of the present invention is to provide a unit optimization method, system and medium considering primary frequency regulation and stabilization measures. Focusing on the safe operation of a low-inertia power system, a unit combination optimization model that can ensure the frequency safety of the system is given, an objective function with the minimum total power generation cost as the goal is established, and combined with the primary frequency regulation of the system and the dynamic response principle of the system frequency, the frequency change rate, maximum frequency deviation, and quasi-steady-state frequency deviation safety constraints are derived and established, and the maximum frequency deviation safety constraint is linearized in combination with the piecewise linearization technology. Combined with the constraints of the safe operation of the power system, the CPLEX solver is used to solve the established model, and a unit combination optimization scheme that can ensure the frequency stability of the power system is obtained, and the effectiveness of the relevant constraints is verified.

[0006] The present invention is achieved through the following technical solutions:

[0007] This solution provides a unit optimization method that takes into account primary frequency regulation and stabilization measures, including:

[0008] Obtaining power system unit operation data;

[0009] The objective function is established with the goal of minimizing the total operating cost of the power system. The safety constraints of the frequency change rate, the maximum frequency deviation and the quasi-steady-state frequency deviation are determined by combining the primary frequency regulation of the unit and the load, the dynamic response process of the system frequency after the power disturbance, and the spare capacity of the unit.

[0010] Considering the primary frequency regulation effect of the generator set and the rapid frequency regulation effect of the stabilization control measures, combined with the characteristics of the fixed ramp rate of the unit, the maximum frequency deviation safety constraint condition is piecewise linearized to obtain a linearized maximum frequency deviation safety constraint condition;

[0011] Adding system power balance constraints, unit spinning reserve constraints, unit output constraints and DC power flow constraints to the objective function;

[0012] The objective function is solved based on the CPLEX solver to obtain the optimal combination of power system units.

[0013] A further optimization scheme is to establish an objective function with the goal of minimizing the total operating cost of the power system, including the following method:

[0014]

[0015] Where F represents the total power generation cost, represents the coal burning cost of unit i, P i,t represents the real-time output of unit i in period t, represents the startup cost of unit i, represents the shutdown cost of unit i, and N represents the total number of units.

[0016] A further optimization scheme is: 3. The unit optimization method considering primary frequency regulation and stabilization measures according to claim 1 is characterized in that the frequency change rate safety constraint condition includes:

[0017]

[0018] in, represents the rate of change of system frequency, H represents the total inertia constant of the system, RoCoF max Indicates the maximum frequency change rate safety value, ΔP OL Indicates the magnitude of active power disturbance; ΔP m Indicates the change in the system's mechanical power; k D It represents the load frequency regulation effect coefficient, and Δf represents the system frequency change.

[0019] A further optimization scheme is: 4. The unit optimization method considering primary frequency regulation and stabilization measures according to claim 3 is characterized in that the maximum frequency deviation safety constraint condition includes:

[0020]

[0021] Where K is the unit speed governor gain coefficient, ω n represents the natural oscillation angular frequency, is the damping ratio, ω r represents the damping angular frequency, α represents the preset parameter, t m Indicates the time when the system frequency deviation reaches the maximum, Δf m Indicates the maximum frequency deviation of the system, Indicates the maximum frequency deviation safety value.

[0022] A further optimization scheme is that the quasi-steady-state frequency deviation safety constraint condition includes:

[0023]

[0024] Where Δf ss Represents the quasi-steady-state frequency deviation of the system, ΔP ∑G It represents the total primary regulation power of the units with primary frequency regulation capability in the system. Indicates the quasi-steady-state frequency deviation safety value.

[0025] The further optimization scheme is that the primary frequency regulation result of the generator set is:

[0026]

[0027] Among them, R s Indicates the system's primary frequency modulation rate, P sp Indicates the power output of the stabilization measure, t sp Indicates the moment when the stabilizing device starts to work.

[0028] A further optimization scheme is that the linearized maximum frequency deviation safety constraint condition includes:

[0029]

[0030] Among them, f N Indicates the system rated frequency, Indicates the lowest safety value of the system frequency.

[0031] A further optimization scheme is that the system power balance constraints include:

[0032]

[0033] Among them, N L represents the number of load nodes, P b,t represents the power consumed by the load of node b in time period t;

[0034] The unit spinning reserve constraint conditions include:

[0035]

[0036] Among them, u i,t represents the start and stop status of unit i in period t, u i,t =1 indicates the unit is started, u i,t =0 means the unit is stopped; P i,max represents the upper limit of the output of unit i, ρ represents the hot standby coefficient of the unit,

[0037] The unit output constraints include:

[0038] u i,t P i,min ≤P i ≤u i,t P i,max ;

[0039] Among them, P i,max , P i,min Respectively represent the upper and lower limits of the output of unit i, P i represents the output of unit i;

[0040] The DC power flow constraint conditions include:

[0041]

[0042] Among them, P l,max , P l,min They represent the maximum and minimum power flows of line l, G l-i It represents the influence of the injected power of node i on line l.

[0043] This solution also provides a unit optimization system considering primary frequency regulation and stabilization measures, which is used to implement the above-mentioned unit optimization method considering primary frequency regulation and stabilization measures; the system includes:

[0044] A collection module is used to obtain the operation data of power system units;

[0045] A construction module is used to establish an objective function with the goal of minimizing the total operating cost of the power system, and to determine the frequency change rate safety constraint, the maximum frequency deviation safety constraint, and the quasi-steady-state frequency deviation safety constraint by combining the primary frequency regulation of the unit and the load, the dynamic response process of the system frequency after the power disturbance, and the spare capacity of the unit;

[0046] A processing module is used to consider the primary frequency regulation effect of the generator set and the rapid frequency regulation effect of the stabilization control measures, and in combination with the characteristics of the fixed ramp rate of the generator set, to perform piecewise linearization processing on the maximum frequency deviation safety constraint condition to obtain a linearized maximum frequency deviation safety constraint condition;

[0047] A constraint module, used for adding system power balance constraint conditions, unit spinning reserve constraint conditions, unit output constraint conditions and DC power flow constraint conditions to the objective function;

[0048] The solution module is used to solve the objective function based on the CPLEX solver to obtain the optimal combination of power system units.

[0049] The present solution also provides a computer-readable medium on which a computer program is stored. The computer program is executed by a processor to implement the unit optimization method considering primary frequency regulation and stabilization measures as described above.

[0050] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0051] The present invention provides a unit optimization method, system and medium considering primary frequency regulation and stabilization measures; focusing on the safe operation of a low-inertia power system, a unit combination optimization model capable of ensuring the safety of the system frequency is provided, an objective function with the minimum total power generation cost as the goal is established, and the frequency change rate, maximum frequency deviation and quasi-steady-state frequency deviation safety constraints are derived and established in combination with the primary frequency regulation of the system and the dynamic response principle of the system frequency. The maximum frequency deviation safety constraint is linearized in combination with the piecewise linearization technology, and the established model is solved by using the CPLEX solver in combination with the constraints of the safe operation of the power system to obtain a unit combination optimization scheme capable of ensuring the stability of the power system frequency, and the effectiveness of the relevant constraints is verified. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0053] Figure 1 The flow chart of the unit optimization method considering primary frequency regulation and stabilization measures;

[0054] Figure 2 It is the dynamic diagram of frequency change after power disturbance occurs in the system;

[0055] Figure 3Linearization schematic diagram for maximum frequency deviation safety constraint;

[0056] Figure 4 This is the system wiring diagram of Example 3;

[0057] Figure 5 This is the 24h total load curve of the system in Example 3;

[0058] Figure 6 The unit combination optimization scheme A obtained in Example 3;

[0059] Figure 7 This is the unit combination optimization scheme B obtained in Example 3. DETAILED DESCRIPTION

[0060] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0061] The traditional maximum frequency deviation safety constraint linearization method only considers the primary frequency regulation of the generator set, and cannot guarantee the safe and stable operation of the power system when a major fault such as a large-capacity unit tripping or DC locking occurs in the system, and the frequency safety problem cannot be effectively solved. In view of this, this solution provides the following embodiments to solve the above technical problems:

[0062] Example 1

[0063] This embodiment provides a unit optimization method considering primary frequency regulation and stabilization measures, such as Figure 1 As shown, including:

[0064] Step 1, obtaining the power system unit operation data;

[0065] Step 2: Establish an objective function with the goal of minimizing the total operating cost of the power system. Combine the primary frequency regulation of the unit and load, the dynamic response process of the system frequency after power disturbance, and the spare capacity of the unit to determine the frequency change rate safety constraint, the maximum frequency deviation safety constraint, and the quasi-steady-state frequency deviation safety constraint. In the process of establishing the objective function, the coal consumption cost of the unit in the system and the start-up and shutdown cost of the unit are considered to obtain the objective function:

[0066]

[0067] Where F represents the total power generation cost, represents the coal burning cost of unit i, P i,t represents the real-time output of unit i in period t, represents the startup cost of unit i, represents the shutdown cost of unit i, and N represents the total number of units.

[0068] In general, the coal consumption cost function of unit i can be expressed by a quadratic function:

[0069]

[0070] Among them, a i 、b i 、c i Represents the coal consumption coefficient of unit i. To facilitate the subsequent solution, the piecewise linearization technology is used to linearize the nonlinear coal consumption cost function. After derivation of formula (2), the slope expression of the coal consumption function is obtained:

[0071] K i,t (P i,t )=a i P i,t +b i (3);

[0072] The coal consumption function is divided into m segments, and the coal consumption function of the original model is replaced by:

[0073]

[0074] Among them, K i,s is the slope of each section of the coal consumption function after piecewise linearization, p i,t,s is the output of the sth segment of the segmented part of unit i in time period t, C 0,i The coal consumption cost generated when the unit is started and running at minimum output, where the relationship satisfied is as follows:

[0075]

[0076] like Figure 2 As shown in the figure, after the active disturbance occurs, under the action of the corresponding stabilization measures of the power system, the rate of change of the system frequency gradually decreases. At the moment when the power system is disturbed, the absolute value of the frequency change rate reaches the maximum. According to the system frequency response model (SFR), the dynamic change process of the system frequency is:

[0077]

[0078] Among them, ΔP OL Indicates the magnitude of active power disturbance, ΔP m is the change in the mechanical power of the system, H is the total inertia constant of the system, is the system frequency change rate, k D is the load frequency regulation effect coefficient, and Δf is the system frequency change.

[0079] Rearranging formula (6) yields:

[0080]

[0081] At the moment of power disturbance, When the system frequency change reaches the maximum value, the absolute value of the frequency change rate also reaches the maximum value. Therefore, the frequency change rate safety constraint expression is:

[0082]

[0083] After the system is disturbed, combined with the frequency deviation expression of the single-machine system frequency response SFR model, the expression can be obtained:

[0084]

[0085] Where K is the unit speed governor gain coefficient, ω n is the natural oscillation angular frequency, is the damping ratio, ω r is the damping angular frequency, α and It is a parameter preset when deriving the frequency deviation expression.

[0086] Differentiating formula (9) yields:

[0087]

[0088] in, TR is the reheat time constant of the unit. The time when the system frequency deviation reaches the maximum can be obtained:

[0089]

[0090] Substituting equation (11) into equation (9) yields the maximum frequency deviation of the system after the disturbance occurs, and the maximum frequency deviation safety constraint is:

[0091]

[0092] Combined with the principle of primary frequency regulation of power system, the expression of quasi-steady-state frequency deviation of power system is:

[0093]

[0094] Among them, ΔP ∑G It represents the total primary regulation power of the units with primary frequency regulation capability in the system; thus, the quasi-steady-state frequency deviation safety constraints include:

[0095]

[0096] Where Δf ssrepresents the quasi-steady-state frequency deviation of the system, Indicates the quasi-steady-state frequency deviation safety value

[0097] Step 3: Considering the primary frequency regulation effect of the generator set and the rapid frequency regulation effect of the stabilization control measures, combined with the characteristics of the fixed ramp rate of the generator set, the maximum frequency deviation safety constraint condition is piecewise linearized to obtain a linearized maximum frequency deviation safety constraint condition;

[0098] Considering the primary frequency regulation of the unit and the frequency regulation of the stabilization measures, it is assumed that the fault occurs at the initial time, that is, t = 0, and at t m At the moment the system frequency deviation reaches the maximum, the equation (6) from 0 to t m Integrating over time periods yields:

[0099]

[0100] In this fault condition, the system frequency gradually deviates from the initial rated frequency and soon crosses the primary frequency regulation dead zone of the generator set. The primary frequency regulation of the generator set begins to take effect. Figure 3 As shown, at t db The frequency modulation starts to work at the first moment. When the preset delay time t of the system stabilization measure is reached sp At this moment, the stabilizing device and the primary frequency modulation work together to maintain the stability of the system frequency. When the sum of the primary frequency modulation output power and the stabilizing device output power equals the system power deficit - ΔP OL When the system frequency reaches the extreme point, the corresponding time is t m .

[0101] Figure 3 The piecewise linearization method is used to simulate the frequency modulation process of the system after a power shortage accident occurs. db ~t sp The time period is much shorter than t sp ~t m , so t can be ignored db ~t sp The primary frequency regulation function of the unit in the time period, that is, the neglected ΔP', in the actual work of the power system, the frequency regulation capacity of the generator set is larger and can better resist external power disturbances.

[0102] The primary frequency regulation rate of the power system is as follows:

[0103]

[0104] Among them, R s Indicates the system's primary frequency modulation rate, P sp Indicates the power output of the stabilization measure, t sp Indicates the moment when the stabilizing device starts to work.

[0105] based on Figure 3 The linearization method shown is used to solve equation (15), and we can obtain:

[0106]

[0107] Among them, W1, W2, and W3 are the system active unbalanced power in the range of 0 to t db , t db ~t sp , t sp ~t m The integral value of the time period, ΔP' is 0~t db The effect of the system's frequency modulation within a time period.

[0108] Substituting equations (16) and (17) into equation (18), we can get the frequency value corresponding to the lowest point of the system frequency. Therefore, the safety constraint condition of the maximum frequency deviation (the lowest point of the system frequency) is:

[0109]

[0110]

[0111] Among them, f N Indicates the system rated frequency, Indicates the lowest safety value of the system frequency.

[0112] Step 4: To ensure safe and stable operation of the system, the objective function should be restricted and constrained, and the objective function should be added with system power balance constraints, unit spinning reserve constraints, unit output constraints, unit climbing constraints, unit start and stop time constraints, unit start and stop cost constraints, DC power flow constraints and frequency safety constraints;

[0113] The system power balance constraints include:

[0114]

[0115] Among them, N L represents the number of load nodes, P b,t represents the power consumed by the load of node b in time period t;

[0116] The unit spinning reserve constraint conditions include:

[0117]

[0118] Among them, u i,t represents the start and stop status of unit i in period t, u i,t =1 indicates the unit is started, u i,t=0 means the unit is stopped; P i,max represents the upper limit of the output of unit i, ρ represents the hot standby coefficient of the unit,

[0119] The unit output constraints include:

[0120] u i,t P i,min ≤P i ≤u i,t P i,max (twenty four);

[0121] Among them, P i,max , P i,min Respectively represent the upper and lower limits of the output of unit i, P i represents the output of unit i;

[0122] The climbing constraint expression of the unit is:

[0123] -R d ≤P i,t -P i,t-1 ≤R u (25);

[0124] Among them, R d , R u Respectively refer to the descending and ascending climbing rates of the generator set.

[0125] The start and stop time constraint expression of the unit is:

[0126]

[0127] Among them, TS and TO represent the minimum shutdown and startup time of the unit respectively.

[0128] The constraint expression of unit startup cost is:

[0129]

[0130] The constraint expression of unit shutdown cost is:

[0131]

[0132] Among them, H i , J i They represent the cost of starting and shutting down each time unit i is started.

[0133] DC power flow constraints include:

[0134]

[0135] Among them, P l,max , P l,minThey represent the maximum and minimum power flows of line l, G l-i It represents the influence of the injected power of node i on line l.

[0136] Step 5: Solve the objective function based on the CPLEX solver to obtain the optimal combination of power system units; the specific process of this step is: the constructed objective function covers two types of decision variables: on the one hand, the power generation of the generator set in each time period is a continuous variable; on the other hand, the start and stop decision of the unit in each time period is a 0-1 variable. It belongs to the mixed integer programming problem (MIP), and the CPLEX solver is good at handling mixed integer programming problems, so CPLEX is selected as the solver to solve this MIP problem.

[0137] Example 2

[0138] This embodiment provides a unit optimization system considering primary frequency regulation and stabilization measures, which is used to implement the unit optimization method considering primary frequency regulation and stabilization measures described in Embodiment 1; the system includes:

[0139] A collection module is used to obtain the operation data of power system units;

[0140] A construction module is used to establish an objective function with the goal of minimizing the total operating cost of the power system, and to determine the frequency change rate safety constraint, the maximum frequency deviation safety constraint, and the quasi-steady-state frequency deviation safety constraint by combining the primary frequency regulation of the unit and the load, the dynamic response process of the system frequency after the power disturbance, and the spare capacity of the unit;

[0141] A processing module is used to consider the primary frequency regulation effect of the generator set and the rapid frequency regulation effect of the stabilization control measures, and in combination with the characteristics of the fixed ramp rate of the generator set, to perform piecewise linearization processing on the maximum frequency deviation safety constraint condition to obtain a linearized maximum frequency deviation safety constraint condition;

[0142] A constraint module, used for adding system power balance constraint conditions, unit spinning reserve constraint conditions, unit output constraint conditions and DC power flow constraint conditions to the objective function;

[0143] The solution module is used to solve the objective function based on the CPLEX solver to obtain the optimal combination of power system units.

[0144] Example 3

[0145] This embodiment provides a computer-readable medium on which a computer program is stored. The computer program is executed by a processor to implement the unit optimization method considering primary frequency regulation and stabilization measures as described in Embodiment 1; specifically, the following steps are performed:

[0146] Step 1, obtaining the power system unit operation data;

[0147] Step 2: Establish an objective function with the goal of minimizing the total operating cost of the power system, combine the primary frequency regulation of the unit and the load, the dynamic response process of the system frequency after the power disturbance, and the spare capacity of the unit to determine the frequency change rate safety constraint, the maximum frequency deviation safety constraint, and the quasi-steady-state frequency deviation safety constraint;

[0148] Step 3: Considering the primary frequency regulation effect of the generator set and the rapid frequency regulation effect of the stabilization control measures, combined with the characteristics of the fixed ramp rate of the generator set, the maximum frequency deviation safety constraint condition is piecewise linearized to obtain a linearized maximum frequency deviation safety constraint condition;

[0149] Step 4, adding system power balance constraints, unit spinning reserve constraints, unit output constraints and DC power flow constraints to the objective function;

[0150] Step 5: Solve the objective function based on the CPLEX solver to obtain the optimal combination of power system units.

[0151] like Figure 4 and Figure 5 As described above, this scheme uses a 6-machine 30-node 41-branch system for example analysis. The system includes 5 thermal power units and 1 wind turbine unit. The known unit parameters include: unit number, unit node number, unit output upper and lower limits, coal consumption function coefficient, unit climbing rate, minimum startup and shutdown time, unit startup and shutdown cost, unit inertia time constant, unit unit regulation power and unit primary frequency regulation rate. The known network parameters include: branch reactance, 1 / 2 charging susceptance, branch flow upper and lower limits. The known load parameters include: the power consumed by each load node in 24 time periods, the total load consumed by the load node in each time period, and the power disturbance in each time period.

[0152] Among them, the main parameters of the power system are shown in Table 1:

[0153] Table 1 Main parameters of the power system

[0154]

[0155] After the system has a power disturbance with the same per-unit value in the first period, the unit combination optimization result is Figure 6 and Figure 7 As shown:

[0156] The results of the unit commitment optimization considering the frequency stability of the power system are solved using the CPLEX solver. Figure 6As shown in Figure 1, taking period 1 as an example, after the power disturbance occurs in the system, units 1, 2, 4, and 6 start to output, and the height of the bar graph represents the output size of the unit. The results of the unit combination optimization without considering the frequency stability of the power system using the CPLEX solver are as follows: Figure 7 As shown, taking time period 1 as an example, after the power disturbance occurs in the system, units 1, 2, and 6 start to output. The height of the bar graph represents the output size of the unit. Compared with the solution considering frequency stability, it is found that unit 4 is started when considering frequency stability and participates in frequency modulation to maintain the frequency safety of the system. The implementation of the embodiment of the present invention has the following beneficial effects:

[0157] The present invention focuses on the safe operation of low-inertia power systems, provides a unit combination optimization model that can ensure the safety of system frequency, establishes an objective function with the minimum total power generation cost as the goal, combines the system primary frequency regulation and the dynamic response principle of the system frequency, derives and establishes frequency change rate, maximum frequency deviation, quasi-steady-state frequency deviation safety constraints, and linearizes the maximum frequency deviation safety constraint in combination with the piecewise linearization technology. Combined with the constraints of the safe operation of the power system, the established model is solved by the CPLEX solver to obtain a unit combination optimization scheme that can ensure the stability of the power system frequency, and the effectiveness of the relevant constraints is verified.

[0158] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A unit optimization method considering primary frequency regulation and stabilization measures, characterized in that: include: Obtaining power system unit operation data; The objective function is established with the goal of minimizing the total operating cost of the power system. The safety constraints of the frequency change rate, the maximum frequency deviation and the quasi-steady-state frequency deviation are determined by combining the primary frequency regulation of the unit and the load, the dynamic response process of the system frequency after the power disturbance, and the spare capacity of the unit. Considering the primary frequency regulation effect of the generator set and the rapid frequency regulation effect of the stabilization control measures, combined with the characteristics of the fixed ramp rate of the unit, the maximum frequency deviation safety constraint condition is piecewise linearized to obtain a linearized maximum frequency deviation safety constraint condition; Adding system power balance constraints, unit spinning reserve constraints, unit output constraints and DC power flow constraints to the objective function; The objective function is solved based on the CPLEX solver to obtain the optimal combination of power system units.

2. The unit optimization method considering primary frequency regulation and stabilization measures according to claim 1 is characterized in that: The objective function is established with the minimum total operating cost of the power system as the goal, including the following method: Where F represents the total power generation cost, C i f represents the coal burning cost of unit i, P i,t represents the real-time output of unit i in period t, C i U represents the startup cost of unit i, C i D represents the shutdown cost of unit i, and N represents the total number of units.

3. The unit optimization method considering primary frequency regulation and stabilization measures according to claim 1 is characterized in that: The frequency change rate safety constraint conditions include: in, represents the rate of change of system frequency, H represents the total inertia constant of the system, RoCoF max Indicates the maximum frequency change rate safety value, ΔP OL Indicates the magnitude of active power disturbance; ΔP m Indicates the change in the system's mechanical power; k D It represents the load frequency regulation effect coefficient, and Δf represents the system frequency change.

4. The unit optimization method considering primary frequency regulation and stabilization measures according to claim 3 is characterized in that: The maximum frequency deviation safety constraint conditions include: Where K is the unit speed governor gain coefficient, ω n represents the natural oscillation angular frequency, is the damping ratio, ω r represents the damping angular frequency, α represents the preset parameter, t m Indicates the time when the system frequency deviation reaches the maximum, Δf m Indicates the maximum frequency deviation of the system, Indicates the maximum frequency deviation safety value.

5. The unit optimization method considering primary frequency regulation and stabilization measures according to claim 4 is characterized in that: The quasi-steady-state frequency deviation safety constraint conditions include: Where Δf ss Represents the quasi-steady-state frequency deviation of the system, ΔP ∑G It represents the total primary regulation power of the units with primary frequency regulation capability in the system. Indicates the quasi-steady-state frequency deviation safety value.

6. The unit optimization method considering primary frequency regulation and stabilization measures according to claim 5 is characterized in that: The primary frequency regulation result of the generator set is: Among them, R s Indicates the system's primary frequency modulation rate, P sp Indicates the power output of the stabilization measure, t sp Indicates the moment when the stabilizing device starts to work.

7. The unit optimization method considering primary frequency regulation and stabilization measures according to claim 6 is characterized in that: The linearized maximum frequency deviation safety constraint condition includes: Among them, f N Indicates the system rated frequency, Indicates the lowest safety value of the system frequency.

8. The unit optimization method considering primary frequency regulation and stabilization measures according to claim 2 is characterized in that: The system power balance constraints include: Among them, N L represents the number of load nodes, P b,t represents the power consumed by the load of node b in time period t; The unit spinning reserve constraint conditions include: Among them, u i,t represents the start and stop status of unit i in period t, u i,t =1 indicates the unit is started, u i,t =0 means the unit is stopped; P i,max represents the upper limit of the output of unit i, ρ represents the hot standby coefficient of the unit, The unit output constraint conditions include: u i,t Q i,min ≤P i ≤u i,t Q i,max ; Among them, P i,max , P i,min Respectively represent the upper and lower limits of the output of unit i, P i represents the output of unit i; The DC power flow constraint conditions include: Among them, P l,max , P l,min They represent the maximum and minimum power flows of line l, G l-i It represents the influence of the injected power of node i on line l.

9. The unit optimization system considering primary frequency regulation and stabilization measures is characterized by: A unit optimization method considering primary frequency regulation and stabilization measures as described in any one of claims 1 to 8 is used to implement the system comprising: A collection module is used to obtain the operation data of power system units; A construction module is used to establish an objective function with the goal of minimizing the total operating cost of the power system, and to determine the frequency change rate safety constraint, the maximum frequency deviation safety constraint, and the quasi-steady-state frequency deviation safety constraint by combining the primary frequency regulation of the unit and the load, the dynamic response process of the system frequency after the power disturbance, and the spare capacity of the unit; A processing module is used to consider the primary frequency regulation effect of the generator set and the rapid frequency regulation effect of the stabilization control measures, and in combination with the characteristics of the fixed ramp rate of the generator set, to perform piecewise linearization processing on the maximum frequency deviation safety constraint condition to obtain a linearized maximum frequency deviation safety constraint condition; A constraint module, used for adding system power balance constraint conditions, unit spinning reserve constraint conditions, unit output constraint conditions and DC power flow constraint conditions to the objective function; The solution module is used to solve the objective function based on the CPLEX solver to obtain the optimal combination of power system units.

10. A computer readable medium having a computer program stored thereon, characterized in that: The computer program is executed by a processor to implement the unit optimization method considering primary frequency regulation and stabilization measures as described in any one of claims 1 to 8.

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