Multi-unit GPSS parameter optimization method and system considering adjustment performance of single unit

Abstract

The invention discloses a multi-machine GPSS parameter optimization method and system considering adjustment performance of a single machine set, and belongs to the technical field of power grid security, and the method comprises the steps: building a frequency low-dimensional dynamic model considering an ultra-low frequency band, building a GPSS model, carrying out the principle analysis, deducing a transfer function of the frequency low-dimensional dynamic model containing the GPSS, and analyzing the property of the transfer function. Constructing an objective function of GPSS parameter setting which comprehensively considers the single-machine regulation performance and the system stability performance, and setting constraint conditions of GPSS parameter setting which comprehensively considers the single-machine regulation performance and the system stability performance. According to the method, rigorous mechanism analysis and parameter optimization are carried out on the GPSS under the condition of considering the adjustment performance of a single unit and the stability performance of the system; the GPSS is subjected to mechanism analysis from the angle of a frequency domain transfer function, the influence of GPSS parameters on the regulation performance and the stability performance of a power system is analyzed, meanwhile, the regulation performance of each unit where the GPSS is installed and the regulation performance of the whole system are improved, and the stability margin is optimized.

Description

Technical Field

[0001] The present invention relates to the technical field of power grid safety, and in particular to a method and system for optimizing parameters of a multi-machine GPSS considering the regulating performance of a single unit. Background Art

[0002] With the large-scale grid connection of new energy power generation, wind power, photovoltaic power and other renewable energy sources have replaced traditional thermal power generation, and the modern power system is gradually moving towards new strategic goals. As a typical hydropower-dominated sending-end power grid, the power grid has repeatedly experienced ultra-low frequency oscillations that are strongly related to the speed regulator and prime mover parameters since asynchronous networking in 2016. The frequency stability problem has gradually become the main risk for the safe and stable operation of the power grid. This risk is becoming more and more obvious in the hydropower-dominated sending-end power grid where the proportion of new energy is gradually increasing.

[0003] The power system stabilizer PSS is a device that compensates for the lagging phase of the excitation system through the leading phase link, thereby providing positive damping torque to the system, increasing the system damping, and suppressing the low-frequency oscillation of the system. However, the effect of PSS in suppressing ultra-low-frequency oscillation will be affected by the load composition, and there is a certain complexity in setting its parameters. The power system stabilizer GPSS on the speed regulator side can directly compensate for the lagging phase of the speed regulator-prime mover, and has a natural advantage in suppressing ultra-low-frequency oscillation caused by the speed regulator dynamics.

[0004] At present, the power grid suppresses ultra-low frequency oscillation by optimizing the PID parameters of the hydropower unit speed regulator, but adjusting the PID parameters will lead to poor system regulation performance and reduced regulation speed. In addition, in actual operation, the frequency will fluctuate frequently and the stability will deteriorate. Therefore, it is necessary to comprehensively consider the system stability and regulation performance, consider adding GPSS devices to achieve this goal, and further enrich and expand the technical means to improve system stability and regulation performance.

[0005] In response to the above problems, this paper comprehensively considers the stability performance and the output speed of the hydro-generator, and from the perspective of frequency domain, derives and verifies the unified frequency model of the frequency domain system, and proposes a multi-machine GPSS parameter tuning method that considers the frequency domain regulation performance of each unit. Using the equivalent model, the properties of the speed governor parameters are fully analyzed from the frequency domain perspective, pointing out that the PID parameter adjustment method is not effective for ultra-low frequency oscillations of the power grid, resulting in a reduction in the regulation speed and inducing frequency fluctuations. At the same time, in the form of transfer functions, the properties and functions of the GPSS parameters are mechanistically analyzed, and the reasons why GPSS introduces other modes are verified and explained. According to the properties of the speed governor and GPSS, a multi-machine GPSS parameter optimization tuning method that considers the regulation speed of each unit separately is proposed. Summary of the invention

[0006] In view of the above-mentioned existing problems, the purpose of the present invention is to solve the shortcomings of the prior art and provide a GPSS mechanism analysis and multi-machine parameter optimization method taking into account the regulation performance of a single unit. The method comprehensively considers the system stability performance and the regulation performance of a single unit on the basis of the original multi-machine parameter setting, improves the stability of the unit under ultra-low frequency oscillation, obtains objective functions and constraints with simple mathematical relationships, and clearly explains the GPSS parameter optimization mechanism.

[0007] In order to solve the above technical problems, a multi-machine GPSS parameter optimization method considering the regulation performance of a single unit is proposed, including:

[0008] Construct a frequency low-dimensional dynamic model considering the ultra-low frequency band; construct the GPSS model and analyze its principles; derive the transfer function of the frequency low-dimensional dynamic model containing GPSS and analyze its properties; construct the objective function for GPSS parameter tuning that comprehensively considers the single-machine regulation performance and system stability performance; set the constraint conditions for GPSS parameter tuning that comprehensively considers the single-machine regulation performance and system stability performance.

[0009] As a preferred solution of the multi-machine GPSS parameter optimization method considering the regulation performance of a single unit described in the present invention, wherein: the frequency low-dimensional dynamic model includes establishing an input reference frequency deviation Δω ref and output mechanical power ΔP m The transfer function matrix between:

[0010]

[0011] Where, ω is the synchronous angular velocity, ω0 is the initial angular velocity of the system, s is the generalized frequency, M is the generator inertia time constant matrix; D is the damping coefficient matrix, P m is the active power matrix of the unit output by the prime mover, P e is the electromagnetic power matrix, K1 is the system linearization coefficient matrix, G Q is the transfer function matrix with the excitation system, Δ refers to its deviation;

[0012] Due to ΔP m =G M (Δω ref -Δω) to get the reference frequency Δω ref The expression is:

[0013]

[0014] Simplified to get ΔP m ≈G M Δω ref , where G M is the transfer function matrix of the speed governor-prime mover system;

[0015] The feedback loop is responsible for the input Δω ref and output ΔP m The feedforward loop between them has little influence, and the prime mover-speed regulator link G M Analog input Δω ref and output ΔP m Based on the dynamics between them, a simplified model of the system, namely the unified frequency domain model, is derived.

[0016] As a preferred solution of the multi-machine GPSS parameter optimization method considering the regulation performance of a single unit described in the present invention, wherein: the GPSS model construction and principle analysis include, for the hydropower-dominated system, GPSS takes the second-order leading link, wherein the leading link is expressed as:

[0017]

[0018] Among them, G c represents the transfer function of the leading link, T a 、T b represents the leading time constant in the first-order leading link, a represents the frequency ratio of the pole-zero point, and 1 / T represents the separation point frequency;

[0019] For the first-order leading link, the maximum value of the leading compensation angle and the corresponding frequency of the maximum compensation angle are:

[0020]

[0021] Among them, φ m is the maximum leading phase, f m To compensate the center frequency, GPSS is a two-order lead-lag link set as:

[0022]

[0023] Among them, K GPSS is the gain parameter of the GPSS link, T a1 、T a2 、T b1 、T b2 are the time constants of the two-order leading links, φ m1 ,φ m2 is the maximum lead phase of the two-order lead link, f m1 、f m2 is the compensation center frequency of the two-order leading link;

[0024] When the GPSS compensation center frequency is determined, the GPSS parameter variable is K GPSS 、T a1 、T a2 、T b1 、T b2Simplified into two-order phase parameter index a1, a2 and gain parameter index K GPSS .

[0025] As a preferred solution of the multi-machine GPSS parameter optimization method considering the regulation performance of a single unit described in the present invention, wherein: the transfer function includes, GPSS takes a second-order leading link to compensate for the phase lag of the prime mover-speed governor link, ignoring the filter and the limiter link, and GPSS takes a second-order leading and lagging link, the speed governor transfer function G with GPSS is obtained M-GPSS as follows:

[0026]

[0027] Among them, G M-GPSS is the speed regulator transfer function, K P , K I , K D is the PID parameter of the speed regulator, b p It represents the permanent slip coefficient;

[0028] In the ultra-low frequency band, the speed regulator link is approximately:

[0029]

[0030] Among them, b p =0.05, GPSS takes the second-order leading link to compensate for the phase lag of the prime mover-speed governor link.

[0031] As a preferred solution of the multi-machine GPSS parameter optimization method considering the regulation performance of a single unit described in the present invention, the objective function includes, for a hydropower-dominated system, setting the parameters of the thermal power unit to be fixed, setting the angular frequency ω, and the characteristics of the system rotor link to lag approximately 90°, which is set by a unified frequency model:

[0032]

[0033] Where L(jω) is the sum of the transfer functions of the speed governor-prime mover and GPSS of each unit in the system, i=1,2…n is the number of the hydropower unit, k=1,2…,m is the number of the thermal power unit, A i , α i are the modulus and phase angle of the i-th unit of the unit respectively;

[0034] In a hydropower-dominated system there are:

[0035]

[0036] According to the generalized Nyquist stability criterion of the multi-input multi-output system, the vector of the point closest to the origin of the generalized Nyquist curve |I+L(s)| is set as the stability margin V of the closed-loop system. M :

[0037]

[0038] The stability margin modulus of the system under ultra-low frequency oscillation is used as the objective function of GPSS parameter design:

[0039]

[0040] Among them, V M is the stability margin vector.

[0041] As a preferred solution of the multi-machine GPSS parameter optimization method considering the regulation performance of a single unit described in the present invention, the constraint conditions include designing time domain performance constraints to ensure that the power response speed of the GPSS system after PI parameter adjustment under different operation modes can meet the performance indicators required by the project:

[0042]

[0043] Among them, t r represents the rise time, t s represents the adjustment time, which transforms the time domain adjustment performance constraint into the frequency domain adjustment performance constraint:

[0044]

[0045] Among them, t smax is the maximum adjustment time, T p,i is the system frequency tracking transfer function, ω B is the bandwidth of the closed-loop transfer function, ω c is the crossover frequency index, K0 is the transition coefficient related to the phase margin, and i represents the i-th hydropower unit where GPSS is installed;

[0046] Add stability constraints as follows:

[0047]

[0048] θ min ≤θ≤θ max

[0049] Among them, θ min ,θ max is the minimum stability margin phase and the maximum stability margin phase.

[0050] As a preferred solution of the multi-machine GPSS parameter optimization method considering the regulation performance of a single unit described in the present invention, wherein: the constraint condition also includes that GPSS uses a second-order leading link to compensate for the phase lag of the prime mover-speed governor link of the hydropower unit to achieve enhanced damping, and the open-loop transfer function is as follows:

[0051]

[0052] For the frequency of ultra-low frequency sweep, the prime mover-speed governor function of the i-th hydro-turbine unit equipped with GPSS needs to meet the phase constraint; the optimal GPSS compensation frequency band is achieved through the center frequency constraint; for the upper and lower bound constraints of GPSS design parameters of different units, the parameters are solved using Matlab according to the optimization conditions.

[0053] Another object of the present invention is to provide a multi-machine GPSS parameter optimization system that takes into account the regulation performance of a single unit. The present invention comprehensively considers the stability performance of the power system and the regulation performance of a single unit, and uses a genetic algorithm to construct the objective function and constraints of GPSS parameter setting to obtain a set of GPSS parameter setting optimization system.

[0054] As a preferred solution of the multi-machine GPSS parameter optimization system considering the regulation performance of a single unit described in the present invention, it is characterized by comprising a model construction module, a transfer function analysis module, a principle analysis module, a function construction module and a condition constraint module;

[0055] The model building module builds a frequency low-dimensional dynamic model considering the ultra-low frequency band;

[0056] The transmission function analysis module, GPSS model construction and principle analysis;

[0057] The principle analysis module derives the transfer function of the frequency low-dimensional dynamic model containing GPSS and analyzes its properties;

[0058] The function construction module constructs the target function of GPSS parameter setting;

[0059] The conditional constraint module sets the constraint conditions for GPSS parameter setting.

[0060] A computer device includes a memory and a processor, wherein the memory stores a computer program, and is characterized in that when the processor executes the computer program, the steps of the multi-machine GPSS parameter optimization method considering the regulation performance of a single unit are implemented.

[0061] 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 multi-machine GPSS parameter optimization method considering the regulation performance of a single unit are implemented.

[0062] Beneficial effects of the invention: The method proposed by the invention provides a GPSS mechanism analysis and multi-machine parameter optimization method considering the regulation performance of a single unit. The method comprehensively considers the system stability performance and the regulation performance of a single unit on the basis of the original multi-machine parameter setting, improves the stability of the unit under ultra-low frequency oscillation, obtains the objective function and constraint conditions with simple mathematical relations, and clearly explains the GPSS parameter optimization mechanism. Compared with the existing methods, the method proposed by the invention is more comprehensive, considering the regulation situation of the actual unit, and has a wider application basis. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0064] Figure 1 An overall flow chart of a multi-machine GPSS parameter optimization method considering the regulation performance of a single unit provided in one embodiment of the present invention.

[0065] Figure 2 A simplified wind turbine grid-connected Heffron-Phillips model diagram of a multi-machine GPSS parameter optimization method considering the regulation performance of a single unit provided in one embodiment of the present invention.

[0066] Figure 3 A system block diagram of a governor-turbine and GPSS according to a method for optimizing parameters of a multi-machine GPSS taking into account the regulating performance of a single unit provided in accordance with an embodiment of the present invention.

[0067] Figure 4 A schematic diagram of the GPSS lead link compensation center of a multi-machine GPSS parameter optimization method considering the regulation performance of a single unit provided in one embodiment of the present invention.

[0068] Figure 5 A definition diagram of the stability margin vector of a multi-machine GPSS parameter optimization method considering the regulation performance of a single unit provided in one embodiment of the present invention.

[0069] Figure 6 A schematic diagram of the modules of a multi-machine GPSS parameter optimization system considering the regulation performance of a single unit provided in accordance with an embodiment of the present invention. DETAILED DESCRIPTION

[0070] In order to make the above-mentioned purposes, 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 drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0071] 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.

[0072] 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 an embodiment that is mutually exclusive with other embodiments, either individually or selectively.

[0073] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0074] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0075] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0076] Example 1, reference Figure 1-Figure 5 , which is the first embodiment of the present invention, provides a multi-machine GPSS parameter optimization method considering the regulation performance of a single unit, including:

[0077] S1: Construct a low-dimensional dynamic model of frequency considering the ultra-low frequency band.

[0078] Construct a low-dimensional dynamic model of frequency considering the ultra-low frequency band, specifically:

[0079] Establishing the input reference frequency deviation Δω ref and output mechanical power ΔP m The transfer function matrix between .

[0080]

[0081] Where, ω is the synchronous angular velocity, ω0 is the initial angular velocity of the system, s is the generalized frequency, M is the generator inertia time constant matrix; D is the damping coefficient matrix, P m is the active power matrix of the unit output by the prime mover, P e is the electromagnetic power matrix, K1 system linearization coefficient matrix, G Q is the transfer function matrix of the excitation system, Δ refers to its deviation, and the solution is ΔP m and Δω are as follows:

[0082]

[0083] And because:

[0084] ΔP m =G M (Δω ref -Δω) (4)

[0085] Among them, G M is the transfer function matrix of the speed regulator-prime mover system; the reference frequency Δω can be obtained ref The expression is:

[0086]

[0087] where Δω ref is the reference frequency, so:

[0088]

[0089] For the sake of simplicity, we can define the transition matrix G IO And the speed response function matrix X(s) is as follows:

[0090]

[0091] G IO is the transition matrix, and X(s) is the speed response function matrix. Substituting equation (8) into equation (7), it is simplified as follows:

[0092]

[0093] Formula (9) can be simplified as follows:

[0094]

[0095] because:

[0096]

[0097] Therefore G IO ≈I, where I is the identity matrix.

[0098] Therefore, from equations (6) and (7), it can be deduced that the above input and output can be approximated as a diagonal relationship:

[0099] ΔP m ≈G M Δω ref (11)

[0100] Furthermore, a simplified model of the system, namely a unified frequency domain model, can be derived, such as Figure 2 shown.

[0101] S2: Construct GPSS model and analyze its principle.

[0102] For the hydropower-dominated system studied in this paper, GPSS takes the second-order leading link, where the leading link can generally be expressed as:

[0103]

[0104] Among them, G c represents the transfer function of the leading link, T a , T b It represents the leading time constant in the first-order leading link, a represents the frequency ratio of the pole-zero point, and 1 / T represents the separation point frequency.

[0105] For the first-order advance link, we have:

[0106]

[0107] Among them, φ m is the maximum leading phase, f m To compensate the center frequency.

[0108] Therefore, GPSS can be set as:

[0109]

[0110] Among them, K GPSS is the gain parameter of the GPSS link, T a1 ,T a2 ,Tb1 ,T b2 are the time constants of the two-order leading links respectively; φ m1 ,φ m2 is the maximum lead phase of the two-order lead link, f m1 , f m2 It compensates the center frequency.

[0111] We need to adjust the maximum angular frequency to the ultra-low frequency range so that the maximum compensation angle is compensated to the oscillation mode, such as Figure 4 shown.

[0112] S3: Derive the transfer function of the frequency-dependent low-dimensional dynamic model containing GPSS and analyze its properties.

[0113] GPSS is a power system stabilizer on the speed regulator side. When the second-order leading link is taken, the transfer function block diagram of the speed regulator with GPSS is as follows: Figure 3 As shown:

[0114]

[0115] Among them, G M-GPSS is the speed regulator transfer function, K P , K I , K D is the PID parameter of the speed regulator, b p Indicates the permanent slip coefficient.

[0116] In the ultra-low frequency band, the speed regulator link is:

[0117]

[0118] Among them, b p Generally, it is 0.05. P <20, PID is a lag link, so the GPSS in the present invention takes a second-order leading link to compensate for the phase lag of the prime mover-speed regulator link.

[0119] S4: Construct an objective function for GPSS parameter tuning that comprehensively considers the single-machine regulation performance and system stability performance.

[0120] The objective function of GPSS parameter tuning is constructed by comprehensively considering the single-machine regulation performance and system stability performance, specifically:

[0121] For the hydropower-dominated system, the unified frequency model is:

[0122]

[0123] L(jω) is the sum of the transfer functions of the speed governor-prime mover and GPSS of each unit in the system, i=1,2…N is the number of the hydropower unit, and k=1,2…,M is the number of the thermal power unit. i ,α i are the module value and phase angle of the i-th unit respectively.

[0124] Furthermore, in a hydropower-dominated system:

[0125]

[0126] Substituting formula (18) into formula (17), we obtain:

[0127]

[0128] The purpose of this parameter setting method is to suppress the inherent ultra-low frequency oscillation mode in the hydropower-dominated system and improve the response performance index of the system. The vector of the point closest to the origin |I+L(s)| is regarded as the stability margin V of the closed-loop system. M :

[0129]

[0130] The stability margin modulus of the system under ultra-low frequency oscillation is used as the objective function of GPSS parameter design:

[0131]

[0132] Among them, V M is the stability margin vector, the stability margin vector is as follows Figure 5 As shown, PM is the phase margin, V M , θ are the modulus and phase of the stability margin vector respectively.

[0133] S5: Set the constraints for GPSS parameter tuning that comprehensively consider the single-machine regulation performance and system stability performance.

[0134] S501 Performance Constraints

[0135] Time Domain Performance Constraints of Design Parameters

[0136]

[0137] Where i represents the i-th unit installed with GPSS, t r represents the rise time, t s Indicates the adjustment time.

[0138] Convert the rise time specification into the bandwidth of the closed-loop transfer function ω B , convert the adjustment time index into the phase margin PM and the crossover frequency index ω c, K0 is the transition coefficient related to the phase margin:

[0139]

[0140] Therefore, the time domain regulation performance constraint (26) can be transformed into the frequency domain regulation performance constraint:

[0141]

[0142] Among them, t smax is the maximum adjustment time, T p,i is the system frequency tracking transfer function.

[0143] S502 Stability Constraint

[0144] Depend on Figure 5 It can be seen that VM refers to the vector closest to the (-1,0) point of the generalized Nyquist curve. |I+L(s)| must satisfy the following conditions: it circles around the origin ρ0 counterclockwise; the system is stable when it does not cross the origin. Therefore:

[0145]

[0146] θ min ≤θ≤θ max (26)

[0147] Among them, θ min ,θ max is the minimum stability margin phase and the maximum stability margin phase.

[0148] S503 Phase Constraint

[0149] For the ultra-low frequency sweep frequencies f1, f2, ..., f Ω , the prime mover-speed governor function of the i-th turbine unit equipped with GPSS needs to satisfy:

[0150] |arg[L i (jω k )]|≈α k -90°≤e p,i ,k=1,2,...,Ω (27)

[0151] Among them, L i (jω) is the open-loop transmission function of the i-th GPSS, e p,i is the upper bound of the phase error of the i-th unit.

[0152] S504 center frequency constraint

[0153] In order to optimize the GPSS compensation frequency band, it is necessary to add constraints to its center frequency:

[0154] fm,min ≤f m ≤f m,max (28)

[0155] Among them, f m,min 、f m,max For the given minimum oscillation frequency and maximum oscillation frequency.

[0156] S505 Other constraints

[0157] For the GPSS of different units, the upper and lower bounds of the designed parameters need to be given according to the actual situation and typical parameters during design.

[0158] According to the given optimization conditions, the parameters are solved using Matlab.

[0159] Example 2, reference Figure 1-Figure 5 , which is the second embodiment of the present invention, provides a multi-machine GPSS parameter optimization method considering the regulation performance of a single unit. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through experiments.

[0160] The parameters of the system GPSS are adjusted using the typical operation mode of Xiada, which is equivalent to A power grid;

[0161] Install GPSS on A1, A2 and A3. After the installation of GPSS, the output of the units is rapidly increased, helping the system to quickly increase the power shortage and improve system stability.

[0162] It can be seen that after installing GPSS, the phase lag of the speed governor output of each unit has been greatly improved, that is, the contribution to stability has increased; the bandwidth of each unit has been improved, that is, the output speed of the unit has been improved; the system damping ratio has turned from negative to positive, with a more obvious improvement.

[0163] Embodiment 3, the third embodiment of the present invention, is different from the first two embodiments in that:

[0164] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, and other media that can store program codes.

[0165] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0166] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0167] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiment, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0168] Example 4, reference Figure 6 , which is the fourth embodiment of the present invention, and provides a multi-machine GPSS parameter optimization system considering the regulation performance of a single unit, including a model construction module 101, a transfer function analysis module 102, a principle analysis module 103, a function construction module 104 and a condition constraint module 105;

[0169] A model building module 101 builds a frequency low-dimensional dynamic model considering an ultra-low frequency band;

[0170] Transmission analysis module 102, GPSS model construction and principle analysis;

[0171] The principle analysis module 103 derives the transfer function of the frequency low-dimensional dynamic model containing GPSS and analyzes its properties;

[0172] Function construction module 104, constructs the target function of GPSS parameter tuning;

[0173] The condition constraint module 105 sets the constraint conditions for GPSS parameter tuning.

[0174] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. 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 multi-machine GPSS parameter optimization method considering the regulation performance of a single unit, characterized by: include, Construct a low-dimensional dynamic model of frequency considering ultra-low frequency band; Conduct GPSS model construction and principle analysis; Derive the transfer function of the frequency-dependent low-dimensional dynamic model containing GPSS and analyze its properties; Construct an objective function for GPSS parameter tuning that comprehensively considers the single-machine regulation performance and system stability performance; Set the constraints for GPSS parameter tuning that comprehensively consider the single-machine regulation performance and system stability performance.

2. The method for optimizing GPSS parameters of multiple units taking into account the regulating performance of a single unit as claimed in claim 1, characterized in that: The frequency low-dimensional dynamic model includes establishing an input reference frequency deviation Δω ref and output mechanical power ΔP m The transfer function matrix between: Where, ω is the synchronous angular velocity, ω0 is the initial angular velocity of the system, s is the generalized frequency, M is the generator inertia time constant matrix; D is the damping coefficient matrix, P m is the active power matrix of the unit output by the prime mover, P e is the electromagnetic power matrix, K1 is the system linearization coefficient matrix, G Q is the transfer function matrix with the excitation system, Δ refers to its deviation; Due to ΔP m =G M (Δω ref -Δω) to get the reference frequency Δω ref The expression is: Simplified to get ΔP m ≈G M Δω ref , where G M is the transfer function matrix of the speed governor-prime mover system; The feedback loop is responsible for the input Δω ref and output ΔP m The feedforward loop between them has little influence, and the G M Analog input Δω ref and output ΔP m Based on the dynamics between them, a simplified model of the system, namely the unified frequency domain model, is derived.

3. The method for optimizing GPSS parameters of multiple units taking into account the regulation performance of a single unit as claimed in claim 2, characterized in that: The GPSS model construction and principle analysis include that for the hydropower-dominated system, GPSS takes the second-order leading link, where the leading link is expressed as: Among them, G c represents the transfer function of the leading link, T a , T b represents the leading time constant in the first-order leading link, a represents the frequency ratio of the pole-zero point, and 1 / T represents the separation point frequency; For the first-order leading link, the maximum value of the leading compensation angle and the corresponding frequency of the maximum compensation angle are: Among them, φ m is the maximum leading phase, f m To compensate the center frequency, GPSS is a two-order lead-lag link set as: Among them, K GPSS is the gain parameter of the GPSS link, T a1 , T a2 , T b1 , T b2 are the time constants of the two-order leading links, φ m1 ,φ m2 is the maximum lead phase of the two-order lead link, f m1 、f m2 is the compensation center frequency of the two-order leading link; When the GPSS compensation center frequency is determined, the GPSS parameter variables are K GPSS , T a1 , T a2 , T b1 , T b2 Simplified into two-order phase parameter index a1, a2 and gain parameter index K GPSS .

4. The method for optimizing GPSS parameters of multiple units taking into account the regulating performance of a single unit as claimed in claim 3, characterized in that: The transfer function includes: GPSS takes the second-order leading link to compensate for the phase lag of the prime mover-speed governor link. When the filter and the limiter link are ignored and GPSS takes the second-order leading and lagging link, the speed governor transfer function G with GPSS is obtained. M-GPSS as follows: Among them, G M-GPSS is the speed regulator transfer function, K P , K I , K D is the PID parameter of the speed regulator, b p It represents the permanent slip coefficient; In the ultra-low frequency band, the speed regulator link is approximately: Among them, b p =0.05, GPSS takes the second-order leading link to compensate for the phase lag of the prime mover-speed governor link.

5. The method for optimizing GPSS parameters of multiple units taking into account the regulating performance of a single unit as claimed in claim 4, characterized in that: The objective function includes, for a hydropower-dominated system, setting the parameters of the thermal power unit to be fixed, setting the angular frequency ω, and the characteristics of the system rotor link to lag approximately 90°, which is set by a unified frequency model: Where L(jω) is the sum of the transfer functions of the speed governor-prime mover and GPSS of each unit in the system, i=1,2…n is the number of the hydropower unit, k=1,2…,m is the number of the thermal power unit, A i , α i are the modulus and phase angle of the i-th unit of the unit respectively; In a hydropower-dominated system there are: According to the generalized Nyquist stability criterion of the multi-input multi-output system, the vector of the point closest to the origin of the generalized Nyquist curve |I+L(s)| is set as the stability margin V of the closed-loop system. M : The stability margin modulus of the system under ultra-low frequency oscillation is used as the objective function of GPSS parameter design: Among them, V M is the stability margin vector.

6. The method for optimizing GPSS parameters of multiple units taking into account the regulating performance of a single unit as claimed in claim 5, characterized in that: The constraints include designing time domain performance constraints to ensure that the power response speed of the GPSS system after PI parameter adjustment in different operation modes can meet the performance indicators required by the project: Among them, t r represents the rise time, t s represents the adjustment time, which converts the time domain adjustment performance constraint into the frequency domain adjustment performance constraint: Among them, t smax is the maximum adjustment time, T p,i is the system frequency tracking transfer function, ω B is the bandwidth of the closed-loop transfer function, ω c is the crossover frequency index, K0 is the transition coefficient related to the phase margin, and i represents the i-th hydropower unit where GPSS is installed; Add stability constraints as follows: i min ≤θ≤θ max Among them, θ min ,θ max is the minimum stability margin phase and the maximum stability margin phase.

7. The method for optimizing GPSS parameters of multiple units taking into account the regulation performance of a single unit as claimed in claim 6, characterized in that: The constraints also include that GPSS uses a second-order leading link to compensate for the phase lag of the prime mover-speed governor link of the hydropower unit to achieve enhanced damping, and the open-loop transfer function is as follows: For the frequency of ultra-low frequency sweep, the prime mover-speed governor function of the i-th hydro-turbine unit equipped with GPSS needs to meet the phase constraint; the optimal GPSS compensation frequency band is achieved through the center frequency constraint; for the upper and lower bound constraints of GPSS design parameters of different units, the parameters are solved using Matlab according to the optimization conditions.

8. A system using the multi-machine GPSS parameter optimization method considering the regulation performance of a single unit as described in any one of claims 1 to 7, characterized in that: It includes model building module, function analysis module, principle analysis module, function building module and condition constraint module; The model building module builds a frequency low-dimensional dynamic model considering the ultra-low frequency band; The transmission function analysis module, GPSS model construction and principle analysis; The principle analysis module derives the transfer function of the frequency low-dimensional dynamic model containing GPSS and analyzes its properties; The function construction module constructs the target function of GPSS parameter setting; The conditional constraint module sets the constraint conditions for GPSS parameter setting.

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 multi-machine GPSS parameter optimization method considering the regulation performance of a single unit are implemented as described in any one of claims 1 to 7.

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 multi-machine GPSS parameter optimization method considering the regulation performance of a single unit are implemented as described in any one of claims 1 to 7.

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