Modeling method and device for electromechanical model of flexible excitation system, medium and product

Abstract

The invention discloses a flexible excitation system electromechanical model modeling method and device, a medium and a product, and the method comprises the steps: constructing an electromechanical model of a power unit; then, building a closed-loop simulation model of the flexible excitation system; wherein the closed-loop simulation model comprises an electromechanical model used for simulating a power unit, a generator model used for simulating a generator, and an excitation regulator; obtaining piecewise linear functions of the maximum excitation voltage, the minimum excitation voltage and the generator terminal voltage; and obtaining a piecewise linear function of the static amplification factor of the power unit and the terminal voltage. According to the invention, on-site excitation system proportion magnification factor measurement and forced excitation capability verification test can be carried out, electromechanical modeling is realized, and a basis is provided for electromechanical transient simulation calculation.

Description

Technical Field

[0001] The present invention belongs to the technical field of power systems, relates to the field of excitation modeling, and in particular to a modeling method, equipment, medium and product of an electromechanical model of a flexible excitation system. Background Art

[0002] The generator excitation system is an important carrier for transient, dynamic and voltage stability control of the power system. At present, the excitation systems widely used in large generators mainly include static excitation and AC excitation machine excitation. The power unit control carrier is a three-phase bridge rectifier circuit based on thyristor (SCR). The mainstream control cycle is generally 20ms, and the control performance has reached the limit.

[0003] In recent years, with the widespread application of power electronic full-control devices represented by IGBT in various fields of power systems, the new flexible excitation system based on IGBT has been industrialized, which can further enhance the excitation control capability and improve the grid-source coordination performance of the unit.

[0004] However, due to changes in power topology and control strategy, the electromechanical model of the conventional self-parallel excitation system can no longer adapt to the flexible excitation system and needs to be improved, which led to this case. Summary of the invention

[0005] The purpose of the present invention is to provide a method, equipment, medium and product for modeling an electromechanical model of a flexible excitation system, which can perform on-site excitation system proportional magnification measurement and strong excitation capability verification test, realize electromechanical modeling, and provide a basis for electromechanical transient simulation calculation.

[0006] In order to achieve the above object, the solution of the present invention is:

[0007] A method for modeling an electromechanical model of a flexible excitation system comprises the following steps:

[0008] Step 1, constructing an electromechanical model of the power unit;

[0009] Step 2, building a closed-loop simulation model of the flexible excitation system; wherein the closed-loop simulation model includes an electromechanical model for simulating a power unit, a generator model for simulating a generator, and an excitation regulator;

[0010] Step 3, obtaining a piecewise linear function of the maximum excitation voltage, the minimum excitation voltage and the machine terminal voltage;

[0011] Step 4, obtaining a piecewise linear function of the static gain of the power unit and the terminal voltage.

[0012] Wherein, in step 1, the electromechanical model includes an adder, a first integrator, a second integrator and a limiter, wherein the positive input terminal of the adder is used to input the voltage control signal U of the excitation regulator C The negative input end of the adder is used to connect the output end of the second integrator; the output end of the adder is connected to the input end of the first integrator, and the output end of the first integrator is respectively connected to the input end of the second integrator and the input end of the limiter, and the limiter is used to output the excitation voltage U f .

[0013] Wherein, the transfer function of the first integrator is:

[0014]

[0015] Among them, K A (U t ) is the terminal voltage U t Related excitation system proportional gain, T A is the time constant of the power unit amplifier, and s is the integration operator.

[0016] Wherein, the transfer function of the second integrator is:

[0017]

[0018] Among them, K F is the power unit stable loop gain, T F is the time constant of the power unit stabilization loop, and s is the integral operator.

[0019] The limiter is used to obtain [V RMIN ,V RMAX ] range, where V RMIN is the minimum excitation voltage, V RMAX is the maximum excitation voltage.

[0020] Wherein, in step 3, given different machine-end voltages, a 15% voltage step test is performed to obtain the corresponding maximum output voltage and minimum output voltage of the excitation regulator, thereby fitting a piecewise linear function of the maximum excitation voltage, the minimum excitation voltage and the machine-end voltage.

[0021] Among them, in the step 4, the excitation current output by the excitation regulator is controlled to increase from zero, the generator voltage rises from 0 to 110% of the rated voltage, the generator voltage and the corresponding internal variables of the excitation regulator are obtained, and the piecewise linear function of the static gain of the power unit and the terminal voltage is calculated.

[0022] A computer device comprises a memory, a processor, and a computer program stored in the memory and executable on the processor; when the processor executes the computer program, the steps of the flexible excitation system electromechanical modeling method as described above are implemented.

[0023] A computer-readable storage medium stores a computer program; when the computer program is executed by a processor, the steps of the flexible excitation system electromechanical modeling method as described above are implemented.

[0024] A computer program product, when executed by a processor, implements the steps of the above-mentioned method for building an electromechanical model of a flexible excitation system.

[0025] After adopting the above scheme, the present invention modifies the excitation system proportional magnification K A and maximum / minimum excitation voltage V RMAX / V RMIN The functional formula can simulate the characteristics of the flexible excitation system, which is not easily affected by the excitation transformer AC voltage and has stronger DC side voltage control capability and strong excitation capability. The electromechanical modeling can be realized through on-site excitation system proportional magnification measurement and strong excitation capability verification test, providing a basis for electromechanical transient simulation calculation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a flow chart of the electromechanical modeling method of the flexible excitation system provided in the present invention;

[0027] Figure 2 It is a block diagram of the electromechanical model of the power unit of the flexible excitation system provided in the present invention;

[0028] Figure 3 It is a wiring diagram of a closed-loop simulation test environment provided in the present invention;

[0029] Figure 4 is the maximum / minimum excitation voltage V RMAX / V RMIN With the terminal voltage U t A piecewise linear function of ;

[0030] Where, (a) is the maximum excitation voltage V RMAX With the terminal voltage U t The piecewise linear function of (b) is the minimum excitation voltage V RMIN With the terminal voltage U t A piecewise linear function of ;

[0031] Figure 5 is the static gain of the power unit K A With the terminal voltage U t A piecewise linear function of . DETAILED DESCRIPTION

[0032] The technical solutions and beneficial effects of the present invention will be described in detail below with reference to the accompanying drawings.

[0033] The grid-related control link of the flexible excitation system is mainly composed of a power unit and an excitation regulator (Automatic Voltage Regulator, AVR for short). The excitation regulator sends a control signal according to the stable operation requirements of the power system and sends it to the power unit for execution. Its electromechanical model is the same as that of the conventional excitation system and will not be repeated here. The power unit is based on a converter based on fully controlled devices and receives the control signal sent by the excitation regulator. It is the main carrier for realizing fast, flexible and high-quality control of the flexible excitation system.

[0034] In conventional self-shunt excitation, the static magnification of the power unit is K A , Maximum excitation voltage V RMAX , minimum excitation voltage V RMIN are constants, however, in the flexible excitation system, these parameters are related to the terminal voltage U t It has a specific piecewise functional relationship and therefore needs to be remodeled.

[0035] For easier understanding, see Figure 1 , the present invention provides an embodiment of a flexible excitation system electromechanical modeling method, the flow chart includes:

[0036] S1. Construct an electromechanical model of the power unit of a flexible excitation system

[0037] In this embodiment, the electromechanical model of the power unit of the flexible excitation system is selected. Figure 2 , in the figure, s is the integral operator, U t is the terminal voltage, U C is the control signal from the excitation regulator, K A is the excitation system proportional magnification, V AMAX / V AMIN is the maximum / minimum internal voltage, U f is the excitation voltage output by the flexible excitation power unit, V RMAX / V RMIN is the maximum / minimum excitation voltage, T A is the time constant of the power unit amplifier, K F is the power unit stable loop gain, T F is the time constant of the power unit stabilization loop.

[0038] In this embodiment, K F =0, T F =0.01, T A =0.01, VAMAX =10, V AMIN =-10.

[0039] S2. Build a closed-loop simulation test environment with power units

[0040] See also Figure 3 Based on the fully digital real-time simulation system ADPSS, a closed-loop simulation test environment including the generator and its excitation, speed control system, PSS, main transformer, main switch and equivalent infinite power supply is built (some parts are not shown in the figure). The dotted box is the digital model built in ADPSS, and the AVR device and power cabinet are physical devices, that is, the two parts of the flexible excitation system. The lines in the figure are signal interactions. ADPSS outputs the generator (G) terminal voltage Ut, terminal current It, excitation current If, etc. to the flexible excitation AVR; the flexible excitation system power cabinet outputs the excitation voltage Uf, and the flexible excitation AVR outputs the voltage control signal Uc to ADPSS, and UET is the excitation transformer anode voltage.

[0041] like Figure 3 As shown in the figure, the ADPSS simulation model simulates the generator stator voltage, stator current, rotor current, rotor voltage and other analog signals during operation and transmits them to the excitation device in real time through the power amplifier device, and the excitation device converts the excitation voltage signal U output by the power cabinet into f Real-time feedback is provided to the ADPSS simulation model to form a closed-loop test environment.

[0042] S3, through the closed-loop simulation test to verify the strong excitation capability, V RMAX / V RMIN The test conditions of the piecewise linear function are: the generator maintains the rated speed, the generator is no-loaded, and the excitation maintains the normal connection mode.

[0043] Test method: For the flexible excitation system, at different machine terminal voltages U t Under the condition of 15% voltage step (up and down) test, measure and record the generator voltage and the generator excitation voltage and excitation current. The maximum output voltage V of the regulator can be measured. RMAX , minimum output voltage V RMIN .

[0044] Table 1 Record of excitation capacity and excitation limit value

[0045]

[0046]

[0047] Finally, the maximum / minimum excitation voltage V is obtained by fitting the record table. RMAX / V RMIN With the terminal voltage U t A piecewise linear function can be matched with Figure 4 As shown, Figure 4 (a) is the maximum excitation voltage V RMAX With the terminal voltage U t The piecewise linear function graph of , Figure 4 (b) is the minimum excitation voltage V RMIN With the terminal voltage U t Graph of a piecewise linear function of .

[0048] S4, through the excitation system proportional magnification measurement closed-loop simulation test fitting to obtain K A Piecewise linear function of

[0049] Test conditions: The generator maintains rated speed and is unloaded. p Set it to about 1 / 10 of the normal operating value, set Ki and Kd to 0, and exit the lead and lag compensation links. Keep the excitation wiring in normal mode.

[0050] Test method: After checking that the output of the automatic excitation regulator of the flexible excitation system is zero, use the automatic excitation regulator to slowly increase the excitation current, adjust the generator voltage from 0 to 110% of the rated voltage, use the wave recording device to measure the generator voltage, rotor voltage and current, and anode voltage, and record the internal variables such as the given voltage, stator measurement voltage, and control voltage of the regulator. Calculate the static magnification K of the power unit of the excitation system A With the terminal voltage U t A piecewise linear function of Figure 5 shown.

[0051] Table 2 Proportional magnification value record table

[0052]

[0053]

[0054] An embodiment of the present invention further provides another computer device, including a processor and a memory configured to store a computer program that can be run on the processor; wherein, when the processor is configured to run the computer program, the method steps in the aforementioned embodiment are executed.

[0055] In practical applications, the processor includes a field programmable gate array (FPGA), and the processor may be a central processing unit (CPU) or a digital signal processor (DSP). It is understandable that for different devices, the electronic device used to implement the function of the processor may be other, and the embodiment of the present invention does not specifically limit it.

[0056] The above-mentioned memory can be a volatile memory (volatile memory), such as a random access memory (RAM); or a non-volatile memory (non-volatile memory), such as a read-only memory (ROM), a flash memory, a hard disk (HDD) or a solid-state drive (SSD); or a combination of the above-mentioned types of memory, and provide instructions and data to the processor.

[0057] In an exemplary embodiment, an embodiment of the present invention further provides a computer-readable storage medium for storing a computer program.

[0058] Optionally, the computer-readable storage medium can be applied to any one of the methods in the embodiments of the present invention, and the computer program enables the computer to execute the corresponding processes implemented by the processor in each method in the embodiments of the present invention. For the sake of brevity, they are not described here.

[0059] In an exemplary embodiment, the present invention further provides a computer program product, which implements the method steps in the above embodiments when executed by a processor.

[0060] In the several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0061] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0062] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0063] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0064] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0065] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0066] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for modeling an electromechanical model of a flexible excitation system, characterized in that The steps include: Step 1, constructing an electromechanical model of the power unit; Step 2, building a closed-loop simulation model of the flexible excitation system; wherein the closed-loop simulation model includes an electromechanical model for simulating a power unit, a generator model for simulating a generator, and an excitation regulator; Step 3, obtaining a piecewise linear function of the maximum excitation voltage, the minimum excitation voltage and the machine terminal voltage; Step 4, obtaining a piecewise linear function of the static gain of the power unit and the terminal voltage.

2. The method according to claim 1, characterized in that: In step 1, the electromechanical model includes an adder, a first integrator, a second integrator and a limiter, wherein the positive input terminal of the adder is used to input the voltage control signal U of the excitation regulator. C The negative input end of the adder is used to connect the output end of the second integrator; the output end of the adder is connected to the input end of the first integrator, and the output end of the first integrator is respectively connected to the input end of the second integrator and the input end of the limiter, and the limiter is used to output the excitation voltage U f .

3. The method according to claim 2, characterized in that: The transfer function of the first integrator is, Among them, K A (U t ) is the terminal voltage U t Related excitation system proportional gain, T A is the time constant of the power unit amplifier, and s is the integration operator.

4. The method according to claim 2, characterized in that: The transfer function of the second integrator is: Among them, K F is the power unit stable loop gain, T F is the time constant of the power unit stabilization loop, and s is the integral operator.

5. The method according to claim 2, characterized in that: The limiter is used to obtain [V RMIN ,V RMAX ] range, where V RMIN is the minimum excitation voltage, V RMAX is the maximum excitation voltage.

6. The method according to claim 1, characterized in that: In step 3, given different machine-end voltages, a 15% voltage step test is performed to obtain the corresponding maximum output voltage and minimum output voltage of the excitation regulator, thereby fitting a piecewise linear function of the maximum excitation voltage, the minimum excitation voltage and the machine-end voltage.

7. The method according to claim 1, characterized in that: In step 4, the excitation current output by the excitation regulator is controlled to increase from zero, the generator voltage rises from 0 to 110% of the rated voltage, the generator voltage and the corresponding internal variables of the excitation regulator are obtained, and the piecewise linear function of the static gain of the power unit and the terminal voltage is calculated.

8. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor; characterized in that: When the processor executes the computer program, the steps of the method for modeling an electromechanical model of a flexible excitation system as described in any one of claims 1 to 7 are implemented.

9. A computer-readable storage medium storing a computer program; characterized in that: When the computer program is executed by a processor, the steps of the method for modeling an electromechanical model of a flexible excitation system as claimed in any one of claims 1 to 7 are implemented.

10. A computer program product, characterized in that: When the computer program product is executed by a processor, the steps of the method for modeling an electromechanical model of a flexible excitation system as claimed in any one of claims 1 to 7 are implemented.

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