Induction motor load frequency response model modeling method and system

Abstract

The invention relates to the technical field of power grid frequency response, and discloses an induction motor load frequency response model modeling method and system. According to the method, circuit equivalence is carried out on the structure of an induction motor, and load flow calculation is carried out on the induction motor; the current slip ratio of the induction motor is updated according to the load flow calculation result of the load node of the induction motor, so that the current slip ratio of the induction motor meets the slip ratio threshold value, and the frequency simulation analysis error of a large power grid is reduced; and the active power consumed by the load node of the induction motor is determined through the updated current slip ratio, so that a load frequency response model about the active power consumed by the load node of the induction motor and the system frequency is constructed, and the accuracy of the load frequency response of the induction motor is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power grid frequency response, and in particular to a modeling method and system for an induction motor load frequency response model. Background Art

[0002] For frequency analysis and calculation, the frequency response model of the equipment is established, such as the speed regulator and prime mover model of the synchronous machine, the FLC control model of the DC equipment and the frequency modulation control model of the new energy equipment, the system rotational inertia is established, and the frequency change trend is analyzed based on the system active power fluctuation. Compared with traditional electromechanical or electromagnetic transient simulation, it has the advantages of fast simulation speed and no need for grid information, and is often used in power grid frequency safety and stability analysis.

[0003] There are many types of loads, including static load models and dynamic load models. Static load models include constant impedance, constant power, and constant current loads, and dynamic load models are mainly induction motor load models. In order to facilitate rapid analysis of system frequency, the frequency response model of static loads is generally considered. However, with the advancement of load modeling and load forecasting technology, unlike static loads, the active power consumed by motor loads is not only related to the voltage amplitude of the load node, but also to the system frequency. For the frequency simulation analysis of actual large power grids, it is easy to cause large errors in the frequency simulation analysis of large power grids, and the accuracy of simulation analysis is low. Summary of the invention

[0004] In view of this, the present invention provides a method and system for modeling an induction motor load frequency response model, which solves the technical problems of large errors in frequency simulation analysis of large power grids and low accuracy of simulation analysis.

[0005] A first aspect of the present invention provides a method for modeling an induction motor load frequency response model, comprising:

[0006] The structure of the induction motor is subjected to circuit equivalence to obtain an equivalent circuit model;

[0007] Performing power flow calculation on the induction motor according to the equivalent circuit model to obtain power flow calculation results of the load nodes of the induction motor;

[0008] updating the current slip rate of the induction motor according to the power flow calculation result of the load node of the induction motor;

[0009] In the case where the updated current slip rate satisfies a preset slip rate threshold, determining the active power consumed by the load node of the induction motor according to the updated current slip rate;

[0010] A load frequency response model of the induction motor is constructed according to the active power consumed by the load node of the induction motor and the system frequency.

[0011] Optionally, the power flow calculation result includes a voltage amplitude and a phase angle of a load node of the induction motor; and the step of updating a current slip rate of the induction motor according to the power flow calculation result of the load node of the induction motor includes:

[0012] Determine a voltage vector value of a load node of the induction motor according to a voltage amplitude and a phase angle of the load node of the induction motor;

[0013] determining electromagnetic power based on a voltage vector value of a load node of the induction motor and a current vector value of a stator resistance and reactance of the induction motor;

[0014] determining the mechanical power according to the rated mechanical power and the current slip rate of the induction motor;

[0015] Based on the rotor motion equation of the induction motor, determining the rate of change of the slip rate of the induction motor according to the electromagnetic power, the mechanical power and the inertia time constant of the induction motor;

[0016] The current slip rate of the induction motor at the next moment is updated according to the change rate of the slip rate of the induction motor.

[0017] Optionally, when the updated current slip rate satisfies a preset slip rate threshold, the step of determining the active power consumed by the load node of the induction motor according to the updated current slip rate comprises:

[0018] Determining whether the updated current slip rate is less than the preset slip rate threshold;

[0019] When it is determined that the updated current slip rate is less than the preset slip rate threshold, the active power consumed by the load node of the induction motor is determined according to the updated current slip rate, the current vector value of the induction motor rotor and the rotor resistance rated value of the induction motor.

[0020] Optionally, the step of constructing a load frequency response model of the induction motor according to the active power consumed by the load node of the induction motor and the system frequency comprises:

[0021] Determining the system frequency change rate according to the active power consumed by the load node of the induction motor at the current simulation moment and the active power consumed at the previous simulation moment, and the inertia time constant of the induction motor;

[0022] Update the current system frequency according to the system frequency change rate, and determine whether the current simulation time is less than the preset simulation time;

[0023] When it is determined that the current simulation time is less than the preset simulation time, the current simulation time is updated according to the preset time step, and the step of performing power flow calculation on the induction motor according to the equivalent circuit model to obtain the power flow calculation result of the load node of the induction motor is performed, until the current simulation time reaches the preset simulation time, the iteration stops and the time variation relationship between the system frequency and the active power is output;

[0024] A load frequency response model of the induction motor is constructed according to the time variation relationship between the system frequency and the active power.

[0025] In a second aspect, the present invention further provides a modeling system for an induction motor load frequency response model, comprising:

[0026] The circuit equivalent module is used to perform circuit equivalent on the structure of the induction motor to obtain an equivalent circuit model;

[0027] A power flow calculation module, used for performing power flow calculation on the induction motor according to the equivalent circuit model to obtain a power flow calculation result of a load node of the induction motor;

[0028] A slip rate updating module, used for updating the current slip rate of the induction motor according to the power flow calculation result of the load node of the induction motor;

[0029] A power calculation module, configured to determine the active power consumed by the load node of the induction motor according to the updated current slip rate when the updated current slip rate satisfies a preset slip rate threshold value;

[0030] The model building module is used to build a load frequency response model of the induction motor according to the active power consumed by the load node of the induction motor and the system frequency.

[0031] Optionally, the power flow calculation result includes the voltage amplitude and phase angle of the load node of the induction motor; and the slip rate updating module includes:

[0032] A voltage determination module, used to determine a voltage vector value of a load node of the induction motor according to a voltage amplitude and a phase angle of the load node of the induction motor;

[0033] An electromagnetic power determination module, used to determine the electromagnetic power according to the voltage vector value of the load node of the induction motor and the current vector value of the stator resistance and reactance of the induction motor;

[0034] A mechanical power determination module, used for determining the mechanical power according to the rated mechanical power and the current slip rate of the induction motor;

[0035] a slip change determination module, configured to determine a change rate of the slip of the induction motor based on a rotor motion equation of the induction motor, according to the electromagnetic power, the mechanical power and an inertia time constant of the induction motor;

[0036] The slip updating module is used to update the current slip of the induction motor at the next moment according to the change rate of the slip of the induction motor.

[0037] Optionally, the power calculation module includes:

[0038] A judging module, used for judging whether the updated current slip rate is less than the preset slip rate threshold;

[0039] The active power determination module is used to determine the active power consumed by the load node of the induction motor according to the updated current slip rate, the current vector value of the induction motor rotor and the rotor resistance rated value of the induction motor when it is determined that the updated current slip rate is less than the preset slip rate threshold value.

[0040] Optionally, the model building module includes:

[0041] A frequency change determination module, used to determine the system frequency change rate according to the active power consumed by the load node of the induction motor at the current simulation moment and the active power consumed at the previous simulation moment, and the inertia time constant of the induction motor;

[0042] Update the current system frequency according to the system frequency change rate, and determine whether the current simulation time is less than the preset simulation time;

[0043] A time variation module, for updating the current simulation time according to the preset time step when it is determined that the current simulation time is less than the preset simulation time, and performing the power flow calculation on the induction motor according to the equivalent circuit model to obtain the power flow calculation result of the load node of the induction motor, until the current simulation time reaches the preset simulation time, the iteration stops and the time variation relationship between the system frequency and the active power is output;

[0044] The response model determination module is used to construct a load frequency response model of the induction motor according to the time variation relationship between the system frequency and the active power.

[0045] In a third aspect, the present invention further provides an electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the induction motor load frequency response modeling method as described in the first aspect.

[0046] In a fourth aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed, the steps of the method for modeling the induction motor load frequency response model as described in the first aspect are implemented.

[0047] It can be seen from the above technical solutions that the present invention makes the structure of the induction motor circuit equivalent, performs power flow calculation on the induction motor, and uses the power flow calculation result of the load node of the induction motor to update the current slip of the induction motor, so that the current slip of the induction motor meets the slip threshold, so as to reduce the error of the frequency simulation analysis of the large power grid, and determines the active power consumed by the load node of the induction motor through the updated current slip, so as to construct a load frequency response model of the active power consumed by the load node of the induction motor and the system frequency, thereby improving the accuracy of the load frequency response of the induction motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 An application environment diagram of a method for modeling a load frequency response model of an induction motor provided by an embodiment of the present invention;

[0049] Figure 2 A flow chart of a method for modeling a load frequency response model of an induction motor provided by an embodiment of the present invention;

[0050] Figure 3 An equivalent circuit model of an induction motor provided by an embodiment of the present invention;

[0051] Figure 4 A schematic diagram of the structure of a system for modeling a load frequency response model of an induction motor provided by an embodiment of the present invention;

[0052] Figure 5 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0053] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] The induction motor load frequency response modeling method provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown. Among them, each device node of the power grid system communicates with the server 102 through the network. The data storage system can store the data that the server 102 needs to process. The data storage system can be integrated on the server 102, or it can be placed on the cloud or other network servers. The server 102 can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides cloud computing services.

[0055] like Figure 2 As shown, the embodiment of the present application provides a method for modeling a load frequency response model of an induction motor, and the method is applied to Figure 1 The server 102 in the example is used as an example to illustrate the method, which includes the following steps S1 to S5. Among them:

[0056] Step S1, performing circuit equivalence on the structure of the induction motor to obtain an equivalent circuit model.

[0057] Among them, the induction motor can be simplified into a load model with constant power factor or constant impedance, current or power. Figure 3 The equivalent circuit model of the induction motor shown in FIG. 1 is shown in FIG. 1 , where U and φ are the voltage amplitude and phase angle of the induction motor terminal node, respectively; R s , X s are the stator resistance and reactance of the induction motor respectively; I s is the current flowing through the stator resistance and reactance of the induction motor, which is a phasor; X m is the magnetizing reactance of the induction motor; R r , X r are the rated value of the rotor resistance and the rotor reactance of the induction motor respectively; s is the slip rate of the induction motor; R=R r / s is the motor rotor resistance correction value after considering the slip rate; I m is the current flowing through the magnetizing reactance of the induction motor, which is a phasor; I r is the current flowing through the rotor resistance of the induction motor and is a phasor.

[0058] Step S2: performing power flow calculation on the induction motor according to the equivalent circuit model to obtain power flow calculation results of the load nodes of the induction motor.

[0059] The power flow calculation results include the voltage amplitude and phase angle of the load node of the induction motor.

[0060] Step S3: updating the current slip rate of the induction motor according to the power flow calculation result of the load node of the induction motor.

[0061] Among them, the slip rate of the induction motor is an important parameter to describe the running state of the motor. It is defined as the difference between the synchronous speed and the actual speed divided by the synchronous speed. When analyzing the frequency response, it is necessary to ensure that the slip rate of the induction motor is extremely small, so as to ensure that the frequency response of the induction motor is more accurate.

[0062] Specifically, the process of updating the current slip rate of the induction motor according to the power flow calculation result of the load node of the induction motor in step S3 includes:

[0063] Step S301: determining a voltage vector value of a load node of the induction motor according to a voltage amplitude and a phase angle of the load node of the induction motor.

[0064] In polar coordinates, the voltage vector is directly described by its amplitude and phase angle.

[0065] Step S302: determining electromagnetic power according to the voltage vector value of the load node of the induction motor and the current vector value of the stator resistance and reactance of the induction motor.

[0066] Among them, the calculation method of electromagnetic power is:

[0067]

[0068] In the formula, is the electromagnetic power, is the voltage vector value of the load node of the induction motor, is the current vector value of the stator resistance and reactance of the induction motor. for:

[0069]

[0070] Where j is the imaginary unit.

[0071] Step S303: determine the mechanical power according to the rated mechanical power and the current slip rate of the induction motor.

[0072] The calculation method of mechanical power is:

[0073]

[0074] In the formula, is the mechanical power, is the rated mechanical power of the induction motor, and A, B, and C are constants of the torque equation.

[0075] Step S304: Based on the rotor motion equation of the induction motor, the change rate of the slip rate of the induction motor is determined according to the electromagnetic power, the mechanical power and the inertia time constant of the induction motor.

[0076] Among them, the rotor motion equation of the induction motor is:

[0077] Where wr is the speed of the induction motor, H is the inertia time constant of the induction motor, and , by Substitute the rotor motion equation of the induction motor into the equation to obtain the rate of change of the induction motor's slip.

[0078] Step S305: updating the current slip rate of the induction motor at the next moment according to the change rate of the slip rate of the induction motor.

[0079] Among them, the current slip rate of the induction motor at the next moment is:

[0080] S(t+1)=s(t)+ ×dt

[0081] Where s(t) and S(t+1) are the slip rates of the induction motor at time t and t+1 respectively.

[0082] Step S4: when the updated current slip rate meets the preset slip rate threshold, determine the active power consumed by the load node of the induction motor according to the updated current slip rate.

[0083] It is necessary to ensure that the current slip rate meets the preset slip rate threshold, that is, the current slip rate should be small enough. Specifically, step S4 specifically includes:

[0084] Step S401: determine whether the updated current slip rate is less than a preset slip rate threshold.

[0085] Step S402: when it is determined that the updated current slip rate is less than the preset slip rate threshold, the active power consumed by the load node of the induction motor is determined according to the updated current slip rate, the current vector value of the induction motor rotor and the rotor resistance rating of the induction motor.

[0086] Among them, the calculation method of the active power consumed by the load node of the induction motor is:

[0087]

[0088] In the formula, is the active power consumed by the load node of the induction motor, is the current vector value of the induction motor rotor. for:

[0089]

[0090] Among them, when it is judged that the updated current slip rate is not less than the preset slip rate threshold, it is necessary to proceed to the step of updating the current slip rate of the induction motor according to the flow calculation result of the load node of the induction motor, until it is judged that the updated current slip rate is less than the preset slip rate threshold, wherein the slip rate threshold can be set to 0.0001pu.

[0091] Step S5: constructing a load frequency response model of the induction motor according to the active power consumed by the load node of the induction motor and the system frequency.

[0092] Among them, the load frequency response model of the induction motor is based on the active external characteristics of the induction motor load when the system frequency changes, and establishes a mathematical function of the system frequency and the active power emitted or absorbed by the equipment. The input variable of the mathematical function is the system frequency f, and the output variable is the active power P output or absorbed by the equipment.

[0093]

[0094] The frequency response model of the induction motor is established to count the unbalanced amount of active power at the global level of the system, and quickly judge the changing trend of the system frequency by the equivalent moment of inertia of the system, so as to obtain relevant data on whether the system has frequency safety and stability risks. Since the slip rate s is a time-varying variable and is related to variables such as system frequency and electromagnetic power, and at the same time, the system reactive support is sufficient or the active disturbance is small, the voltage amplitude of the load node of the induction motor should remain unchanged before and after the disturbance to avoid affecting the frequency response results.

[0095] Specifically, the process of constructing the load frequency response model of the induction motor according to the active power consumed by the load node of the induction motor and the system frequency in step S5 includes:

[0096] Step S501 : determining the system frequency change rate according to the active power consumed by the load node of the induction motor at the current simulation moment, the active power consumed at the previous simulation moment, and the inertia time constant of the induction motor.

[0097] Among them, the system frequency change rate is:

[0098]

[0099] In the formula, is the system frequency, is the system frequency change rate, is the active power consumed at the previous simulation moment.

[0100] Step S502: update the current system frequency according to the system frequency change rate, and determine whether the current simulation time is less than the preset simulation time;

[0101] Step S503: When it is determined that the current simulation time is less than the preset simulation time, the current simulation time is updated according to the preset time step, and the process goes to step S2 until the current simulation time reaches the preset simulation time, the iteration stops, and the time variation relationship between the system frequency and the active power is output.

[0102] Step S504: construct a load frequency response model of the induction motor according to the time variation relationship between the system frequency and the active power.

[0103] It can be understood that the time-varying relationship between system frequency and active power represents the time-varying relationship between system frequency and active power. By fitting the data based on the time-varying relationship between system frequency and active power, we can obtain the functional relationship between system frequency and active power with respect to time, which is the load frequency response model of the induction motor.

[0104] It should be noted that the embodiment of the present application performs circuit equivalence on the structure of the induction motor, performs power flow calculation on the induction motor, and uses the power flow calculation result of the load node of the induction motor to update the current slip of the induction motor, so that the current slip of the induction motor meets the slip threshold, so as to reduce the error of the frequency simulation analysis of the large power grid, and determines the active power consumed by the load node of the induction motor through the updated current slip, so as to construct a load frequency response model of the active power consumed by the load node of the induction motor and the system frequency, thereby improving the accuracy of the load frequency response of the induction motor.

[0105] Based on the same inventive concept, an embodiment of the present application further provides an induction motor load frequency response modeling system for implementing the above-mentioned induction motor load frequency response modeling method.

[0106] The implementation solution for solving the problem provided by the system is similar to the implementation solution recorded in the above method. Therefore, the specific limitations in one or more induction motor load frequency response model modeling system embodiments provided below can refer to the limitations on the induction motor load frequency response model modeling method above, and will not be repeated here.

[0107] like Figure 4 As shown, the embodiment of the present application also provides an induction motor load frequency response modeling system, comprising:

[0108] The circuit equivalent module 100 is used to perform circuit equivalent on the structure of the induction motor to obtain an equivalent circuit model;

[0109] The power flow calculation module 200 is used to perform power flow calculation on the induction motor according to the equivalent circuit model to obtain the power flow calculation result of the load node of the induction motor;

[0110] The slip rate updating module 300 is used to update the current slip rate of the induction motor according to the power flow calculation result of the load node of the induction motor;

[0111] A power calculation module 400, for determining the active power consumed by the load node of the induction motor according to the updated current slip rate when the updated current slip rate meets the preset slip rate threshold value;

[0112] The model building module 500 is used to build a load frequency response model of the induction motor according to the active power consumed by the load node of the induction motor and the system frequency.

[0113] In some embodiments, the power flow calculation result includes the voltage amplitude and phase angle of the load node of the induction motor; the slip rate update module includes:

[0114] A voltage determination module, used to determine a voltage vector value of a load node of the induction motor according to a voltage amplitude and a phase angle of the load node of the induction motor;

[0115] An electromagnetic power determination module, for determining the electromagnetic power according to a voltage vector value of a load node of the induction motor and a current vector value of a stator resistance and reactance of the induction motor;

[0116] A mechanical power determination module, used for determining the mechanical power according to the rated mechanical power and the current slip rate of the induction motor;

[0117] A slip change determination module, for determining a change rate of the slip of the induction motor based on the rotor motion equation of the induction motor, according to the electromagnetic power, the mechanical power and the inertia time constant of the induction motor;

[0118] The slip rate updating module is used to update the current slip rate of the induction motor at the next moment according to the change rate of the slip rate of the induction motor.

[0119] In some embodiments, the power calculation module includes:

[0120] A judging module, used to judge whether the updated current slip rate is less than a preset slip rate threshold;

[0121] The active power determination module is used to determine the active power consumed by the load node of the induction motor according to the updated current slip rate, the current vector value of the induction motor rotor and the rotor resistance rated value of the induction motor when it is determined that the updated current slip rate is less than the preset slip rate threshold value.

[0122] In some embodiments, the model building module includes:

[0123] A frequency change determination module, used to determine the system frequency change rate according to the active power consumed by the load node of the induction motor at the current simulation moment and the active power consumed at the previous simulation moment, and the inertia time constant of the induction motor;

[0124] Update the current system frequency according to the system frequency change rate, and determine whether the current simulation time is less than the preset simulation time;

[0125] A time variation module is used to update the current simulation time according to the preset time step when it is determined that the current simulation time is less than the preset simulation time, and to perform power flow calculation on the induction motor according to the equivalent circuit model to obtain the power flow calculation result of the load node of the induction motor, until the current simulation time reaches the preset simulation time, the iteration stops and the time variation relationship between the system frequency and the active power is output;

[0126] The response model determination module is used to construct a load frequency response model of the induction motor according to the time variation relationship between the system frequency and the active power.

[0127] like Figure 5 As shown, an embodiment of the present application further provides an electronic device, the electronic device 10 includes a memory 20 and a processor 30, the memory 20 stores a computer program, and when the computer program is executed by the processor 30, the processor 30 executes the steps of the induction motor load frequency response modeling method in any of the above embodiments.

[0128] An embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed, the steps of the method for modeling the induction motor load frequency response model in any of the above embodiments are implemented.

[0129] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described system, electronic device and computer storage medium can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0130] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or apparatus.

[0131] In several embodiments provided by the present invention, it is understood that each box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and a part of a module, a program segment or a code includes one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved.

[0132] In the several embodiments provided by the present invention, it should be understood that the disclosed systems, electronic devices, computer storage media and methods can be implemented in other ways. For example, 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 integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0133] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0134] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0135] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or all or 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 executing all or part of the steps of the method described in each embodiment of the present invention through a computer device (which can be a personal computer, server, or network device, etc.). The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (full name in English: Read-Only Memory, English abbreviation: ROM), random access memory (full name in English: Random Access Memory, English abbreviation: RAM), disk or optical disk and other media that can store program codes.

[0136] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for modeling an induction motor load frequency response model, characterized in that: include: The structure of the induction motor is subjected to circuit equivalence to obtain an equivalent circuit model; Performing power flow calculation on the induction motor according to the equivalent circuit model to obtain power flow calculation results of the load nodes of the induction motor; updating the current slip rate of the induction motor according to the power flow calculation result of the load node of the induction motor; In the case where the updated current slip rate satisfies a preset slip rate threshold, determining the active power consumed by the load node of the induction motor according to the updated current slip rate; A load frequency response model of the induction motor is constructed according to the active power consumed by the load node of the induction motor and the system frequency.

2. The method for modeling an induction motor load frequency response model according to claim 1, characterized in that: The power flow calculation result includes the voltage amplitude and phase angle of the load node of the induction motor; The step of updating the current slip rate of the induction motor according to the power flow calculation result of the load node of the induction motor comprises: Determine a voltage vector value of a load node of the induction motor according to a voltage amplitude and a phase angle of the load node of the induction motor; determining electromagnetic power based on a voltage vector value of a load node of the induction motor and a current vector value of a stator resistance and reactance of the induction motor; determining the mechanical power according to the rated mechanical power and the current slip rate of the induction motor; Based on the rotor motion equation of the induction motor, determining the rate of change of the slip rate of the induction motor according to the electromagnetic power, the mechanical power and the inertia time constant of the induction motor; The current slip rate of the induction motor at the next moment is updated according to the change rate of the slip rate of the induction motor.

3. The method for modeling an induction motor load frequency response model according to claim 1, characterized in that: The step of determining the active power consumed by the load node of the induction motor according to the updated current slip rate when the updated current slip rate meets the preset slip rate threshold value comprises: Determining whether the updated current slip rate is less than the preset slip rate threshold; When it is determined that the updated current slip rate is less than the preset slip rate threshold, the active power consumed by the load node of the induction motor is determined according to the updated current slip rate, the current vector value of the induction motor rotor and the rotor resistance rated value of the induction motor.

4. The method for modeling an induction motor load frequency response model according to claim 1, characterized in that: The step of constructing a load frequency response model of the induction motor according to the active power consumed by the load node of the induction motor and the system frequency comprises: Determining the system frequency change rate according to the active power consumed by the load node of the induction motor at the current simulation moment and the active power consumed at the previous simulation moment, and the inertia time constant of the induction motor; Update the current system frequency according to the system frequency change rate, and determine whether the current simulation time is less than the preset simulation time; When it is determined that the current simulation time is less than the preset simulation time, the current simulation time is updated according to the preset time step, and the step of performing power flow calculation on the induction motor according to the equivalent circuit model to obtain the power flow calculation result of the load node of the induction motor is performed, until the current simulation time reaches the preset simulation time, the iteration stops and the time variation relationship between the system frequency and the active power is output; A load frequency response model of the induction motor is constructed according to the time variation relationship between the system frequency and the active power.

5. A modeling system for an induction motor load frequency response model, characterized in that: include: The circuit equivalent module is used to perform circuit equivalent on the structure of the induction motor to obtain an equivalent circuit model; A power flow calculation module, used for performing power flow calculation on the induction motor according to the equivalent circuit model to obtain a power flow calculation result of a load node of the induction motor; A slip rate updating module, used for updating the current slip rate of the induction motor according to the power flow calculation result of the load node of the induction motor; A power calculation module, configured to determine the active power consumed by the load node of the induction motor according to the updated current slip rate when the updated current slip rate satisfies a preset slip rate threshold value; The model building module is used to build a load frequency response model of the induction motor according to the active power consumed by the load node of the induction motor and the system frequency.

6. The induction motor load frequency response modeling system according to claim 5, characterized in that: The power flow calculation result includes the voltage amplitude and phase angle of the load node of the induction motor; The slip rate updating module comprises: A voltage determination module, used to determine a voltage vector value of a load node of the induction motor according to a voltage amplitude and a phase angle of the load node of the induction motor; An electromagnetic power determination module, used to determine the electromagnetic power according to the voltage vector value of the load node of the induction motor and the current vector value of the stator resistance and reactance of the induction motor; A mechanical power determination module, used for determining the mechanical power according to the rated mechanical power and the current slip rate of the induction motor; a slip change determination module, configured to determine a change rate of the slip of the induction motor based on a rotor motion equation of the induction motor, according to the electromagnetic power, the mechanical power and an inertia time constant of the induction motor; The slip updating module is used to update the current slip of the induction motor at the next moment according to the change rate of the slip of the induction motor.

7. The induction motor load frequency response modeling system according to claim 5, characterized in that: The power calculation module comprises: A judging module, used for judging whether the updated current slip rate is less than the preset slip rate threshold; The active power determination module is used to determine the active power consumed by the load node of the induction motor according to the updated current slip rate, the current vector value of the induction motor rotor and the rotor resistance rated value of the induction motor when it is determined that the updated current slip rate is less than the preset slip rate threshold value.

8. The induction motor load frequency response modeling system according to claim 5, characterized in that: The model building module includes: A frequency change determination module, used to determine the system frequency change rate according to the active power consumed by the load node of the induction motor at the current simulation moment and the active power consumed at the previous simulation moment, and the inertia time constant of the induction motor; Update the current system frequency according to the system frequency change rate, and determine whether the current simulation time is less than the preset simulation time; A time variation module, for updating the current simulation time according to the preset time step when it is determined that the current simulation time is less than the preset simulation time, and performing the power flow calculation on the induction motor according to the equivalent circuit model to obtain the power flow calculation result of the load node of the induction motor, until the current simulation time reaches the preset simulation time, the iteration stops and the time variation relationship between the system frequency and the active power is output; The response model determination module is used to construct a load frequency response model of the induction motor according to the time variation relationship between the system frequency and the active power.

9. An electronic device, characterized in that: The electronic device includes a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the steps of the induction motor load frequency response modeling method according to any one of claims 1 to 4.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed, the steps of the method for modeling the induction motor load frequency response model according to any one of claims 1 to 4 are implemented.

Images