A flexible excitation system electromechanical model modeling method, device, medium and product

Abstract

This invention discloses a method, equipment, medium, and product for modeling the electromechanical model of a flexible excitation system. First, an electromechanical model of the power unit is constructed. Then, a closed-loop simulation model of the flexible excitation system is built. The closed-loop simulation model includes an electromechanical model for simulating the power unit, a generator model for simulating the generator, and an excitation regulator. Piecewise linear functions of the maximum excitation voltage, minimum excitation voltage, and generator terminal voltage are obtained. Piecewise linear functions of the static amplification factor of the power unit and the generator terminal voltage are also obtained. This invention enables on-site measurement of the proportional amplification factor of the excitation system and verification tests of the forced excitation capability, achieving electromechanical modeling and providing a basis for electromechanical transient simulation calculations.

Description

Technical Field

[0001] This invention belongs to the field of power system technology, specifically the field of excitation modeling, and particularly relates to a method, equipment, medium, and product for modeling electromechanical models of flexible excitation systems. Background Technology

[0002] The generator excitation system is a crucial component for transient, dynamic, and voltage stability control in power systems. Currently, the excitation systems widely used in large generator sets mainly fall into two categories: static excitation and AC exciter excitation. The power unit control mechanism in both systems is based on a three-phase bridge rectifier circuit using thyristors (SCRs), with a mainstream control cycle of approximately 20ms, indicating that control performance has reached its limit.

[0003] In recent years, with the widespread application of power electronic fully controllable devices represented by IGBTs in various fields of power systems, a new flexible excitation system based on IGBTs has been industrialized. It can further enhance excitation control capabilities 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 conventional self-excited excitation system can no longer be adapted to flexible excitation system and needs to be improved, hence this case. Summary of the Invention

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

[0006] To achieve the above objectives, the solution of the present invention is:

[0007] A method for modeling an electromechanical system for flexible excitation systems includes the following steps:

[0008] Step 1: Construct the electromechanical model of the power unit;

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

[0010] Step 3: Obtain the piecewise linear functions of the maximum excitation voltage, minimum excitation voltage, and terminal voltage;

[0011] Step 4: Obtain the piecewise linear function of the static amplification factor of the power unit and the terminal voltage.

[0012] In step 1, the electromechanical model includes an adder, a first integrator, a second integrator, and a limiter. The positive input of the adder is used to input the voltage control signal U of the excitation regulator. C The negative input terminal of the adder is connected to the output terminal of the second integrator; the output terminal of the adder is connected to the input terminal of the first integrator, and the output terminal of the first integrator is connected to the input terminal of the second integrator and the input terminal of the limiter, respectively. 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 (This is related to the terminal voltage U) t The relevant excitation system proportional gain, T A is the time constant of the power unit amplifier, and s is the integral operator.

[0016] The transfer function of the second integrator is:

[0017]

[0018] Among them, K F For the gain of the power unit's stable circuit, T F Let be the time constant of the stable circuit of the power unit, and s be the integral operator.

[0019] The limiter is used to obtain [V] RMIN V RMAX Voltage signals within the range of ], where V RMIN For the minimum excitation voltage, V RMAX This is the maximum excitation voltage.

[0020] In step 3, given different terminal voltages, a 15% voltage step test is performed to obtain the corresponding maximum and minimum output voltages of the excitation regulator, thereby fitting a piecewise linear function of the maximum and minimum excitation voltages with respect to the terminal voltage.

[0021] In step 4, the excitation current output by the excitation regulator is increased 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 amplification factor of the power unit and the terminal voltage is calculated.

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

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

[0024] A computer program product, when executed by a processor, implements the steps of the electromechanical modeling method for a flexible excitation system as described above.

[0025] After adopting the above scheme, the present invention modifies the proportional amplification factor K of the excitation system. A and maximum / minimum excitation voltage V RMAX / V RMIN The functional model simulates the characteristics of flexible excitation systems, which are not easily affected by AC voltage measurement of the excitation transformer, have stronger DC side voltage control capability and strong excitation capability. Electromechanical modeling can be achieved through on-site excitation system proportional amplification factor measurement and strong excitation capability verification test, providing a basis for electromechanical transient simulation calculation. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the electromechanical modeling method for flexible excitation systems provided in this invention;

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

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

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

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

[0031] Figure 5 It is the static amplification factor K of the power unit. A With terminal voltage U t A piecewise linear function. Detailed Implementation

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

[0033] The grid-connected control link of the flexible excitation system mainly consists of power units and an automatic voltage regulator (AVR). The AVR sends control signals to the power units for execution based on the requirements for stable operation of the power system. Its electromechanical model is the same as that of the conventional excitation system, and will not be described in detail here. The power unit is based on a converter with fully controlled devices and receives the control signals from the AVR. It is the main carrier for realizing fast, flexible and high-quality control of the flexible excitation system.

[0034] In conventional self-excited excitation, the static amplification factor K of the power unit is... A Maximum excitation voltage V RMAX Minimum excitation voltage V RMIN These are constants; however, in flexible excitation systems, these parameters are related to the terminal voltage U. t It exhibits a specific piecewise functional relationship, therefore it needs to be remodeled.

[0035] For easier understanding, please refer to Figure 1 The present invention provides an embodiment of an electromechanical modeling method for a flexible excitation system, the flowchart of which 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. Please refer to [link / reference needed]. Figure 2 In the figure, s is the integral operator, and U t U is the terminal voltage. C K is the control signal sent by the excitation regulator. A V is the proportional gain of the excitation system. AMAX / V AMIN For the maximum / minimum internal voltage, U f V is the excitation voltage output by the flexible excitation power unit. RMAX / V RMIN T represents the maximum / minimum excitation voltage. A K is the time constant of the power unit amplifier. F For the gain of the power unit's stable circuit, T F This is the time constant of the power unit's stabilization loop.

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

[0039] S2. Establish a closed-loop simulation test environment containing power units.

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

[0041] like Figure 3 As shown, the simulated generator stator voltage, stator current, rotor current, and rotor voltage signals generated during operation in the ADPSS simulation model are transmitted in real time to the excitation device via a power amplifier. The excitation device then transmits the excitation voltage signal U output from the power cabinet. f The data is fed back to the ADPSS simulation model in real time, forming a closed-loop test environment.

[0042] S3. V is obtained through closed-loop simulation test fitting for strong excitation capability verification. RMAX / V RMIN Piecewise linear function test conditions: The generator maintains its rated speed, the generator is unloaded, and the excitation is maintained in normal wiring mode.

[0043] Test method: For flexible excitation systems, different terminal voltages U t Under these conditions, a 15% voltage step test (up and down) is performed, and the generator voltage, generator excitation voltage, and excitation current are measured and recorded. 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 was obtained by fitting the record table. RMAX / V RMIN With terminal voltage U t Piecewise linear functions, which can be used in conjunction with Figure 4 As shown, where, Figure 4 (a) is the maximum excitation voltage V RMAX With terminal voltage U t Piecewise linear function graph, Figure 4 (b) is the minimum excitation voltage V RMIN With terminal voltage U t The piecewise linear function graph.

[0048] S4. K is obtained by fitting the closed-loop simulation test of the proportional amplification factor measurement of the excitation system. A Piecewise linear functions

[0049] Test conditions: The generator maintains its rated speed under no-load conditions. The proportional element K of the excitation regulator PID controller is adjusted. p Set the values ​​to approximately 1 / 10 of the normal operating values, set Ki and Kd to 0, and disable the lead and lag compensation circuits. Maintain the normal wiring configuration for excitation.

[0050] Test Method: After confirming that the output of the automatic excitation regulator of the flexible excitation system is zero, slowly increase the excitation current using the automatic excitation regulator, adjusting the generator voltage from 0 to 110% of the rated voltage. Use a waveform recorder to measure and record the generator voltage, rotor voltage, current, and anode voltage. Simultaneously record internal variables such as the regulator's setpoint voltage, stator measured voltage, and control voltage. Calculate the static amplification factor K of the excitation system power unit. A With terminal voltage U t Piecewise linear functions, such as Figure 5 As shown.

[0051] Table 2 Record of Magnification Values

[0052]

[0053]

[0054] This invention also provides another computer device, including a processor and a memory configured to store a computer program capable of running on the processor; wherein, when the processor is configured to run the computer program, it performs the method steps described in the foregoing embodiments.

[0055] In practical applications, the aforementioned processor includes a Field-Programmable Gate Array (FPGA), and the processor can be a Central Processing Unit (CPU) or a Digital Signal Processor (DSP). It is understood that for different devices, the electronic devices used to implement the functions of the aforementioned processor can also be other types, and this embodiment of the invention does not impose specific limitations.

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

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

[0058] Optionally, the computer-readable storage medium can be applied to any of the methods in the embodiments of the present invention, and the computer program causes the computer to execute the corresponding processes implemented by the processor in the various methods of the embodiments of the present invention. For the sake of brevity, these will not be described in detail here.

[0059] In an exemplary embodiment, the present invention also provides a computer program product that, when executed by a processor, implements the method steps described in the foregoing embodiments.

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

[0061] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can 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 code. The solutions in the embodiments of the present invention can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0062] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0063] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0064] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0065] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0066] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A flexible excitation system electromechanical model modeling method, characterized in that The method comprises the following steps: 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 comprises an electromechanical model for simulating the power unit, a generator model for simulating the generator, and an excitation regulator; Step 3, obtaining a segmented linear function of the maximum excitation voltage, the minimum excitation voltage and the terminal voltage; Step 4, obtaining a segmented linear function of the static amplification factor of the power unit and the terminal voltage; In the step 1, the electromechanical model comprises an adder, a first integrator, a second integrator and a limiter, wherein a positive input terminal of the adder is used for inputting a voltage control signal U of the excitation regulator C , a negative input terminal of the adder is used for connecting an output terminal of the second integrator; an output terminal of the adder is connected to an input terminal of the first integrator, an output terminal of the first integrator is respectively connected to an input terminal of the second integrator and an input terminal of the limiter, and the limiter is used for outputting an excitation voltage U f . The transfer function of the first integrator is wherein K A (U t ) is the excitation system proportional gain related to the machine terminal voltage U t , T A is the time constant of the power unit amplifier, and s is the integration operator. The transfer function of the second integrator is where K F is the power unit stabilizing loop gain, T F is the power unit stabilizing loop time constant, and s is the integral operator; In the step 3, given different terminal voltages, perform a 15% voltage step test to obtain the corresponding maximum output voltage and minimum output voltage of the excitation regulator, thereby fitting the segmented linear function of the maximum excitation voltage, the minimum excitation voltage and the terminal voltage; In the step 4, the excitation current output by the excitation regulator is increased from zero, and the generator voltage is increased from 0 to 110% rated voltage, to obtain the generator voltage and the corresponding excitation regulator internal variable, and to calculate the segmented linear function of the static amplification factor of the power unit and the terminal voltage.

2. The method of claim 1, wherein: The limiter is used to obtain a voltage signal in the range of [V RMIN , V RMAX ], where V RMIN is the minimum excitation voltage and V RMAX is the maximum excitation voltage.

3. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor; characterized in that: The processor executes the computer program to realize the steps of the flexible excitation system electromechanical model modeling method according to any one of claims 1 to 2.

4. A computer readable storage medium, the computer readable storage medium storing a computer program; characterized in that: The computer program is executed by the processor to realize the steps of the flexible excitation system electromechanical model modeling method according to any one of claims 1 to 2.

5. A computer program product, characterized by: The computer program product is executed by the processor to realize the steps of the flexible excitation system electromechanical model modeling method according to any one of claims 1 to 2.

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