Method and device for generating inductance parameters of alternating-current excitation motor under all working conditions

Abstract

The invention relates to a method and a device for generating inductance parameters of an alternating-current excitation motor under all working conditions. The method comprises the following steps: constructing a sub-domain model and a magnetic network model corresponding to the excitation motor according to a motor structure of the excitation motor; determining slot current precision information according to the stator current information and the rotor current information under the target working condition, and determining magnetic flux density information and magnetic field intensity distribution information of the excitation motor through a sub-domain model and a magnetic network model under the condition that the slot current precision information meets a preset precision requirement; and determining inductance parameters of the excitation motor according to the magnetic flux density information and the magnetic field intensity distribution information of the excitation motor. By adopting the method, the sub-domain model and the magnetic network model can be constructed by analyzing the relation between the motor structure and the electromagnetic field of the excitation motor, the influence of the current on the inductance of the excitation motor under different working conditions is analyzed based on the sub-domain model and the magnetic network model, and the inductance parameter of the excitation motor is accurately calculated, so that the accuracy of the inductance parameter of the motor is improved.

Description

Technical Field

[0001] The present application relates to the field of mechatronics technology, and particularly to a method, device, computer device, computer-readable storage medium, and computer program product for generating inductance parameters of an AC-excited motor under all operating conditions. Background Art

[0002] With the large-scale access of new energy power sources represented by wind power and photovoltaic power to the power grid, the volatility and randomness of the new energy power generation method itself have increasingly exacerbated the problem of source-load imbalance in the new power system, and large-scale energy storage devices are urgently needed to participate in the power balance of the power grid. The variable-speed pumped-storage power station can store electrical energy on a large scale and has excellent dynamic performance, and is an important device for the power grid to carry out peak shaving and frequency modulation. The large-scale AC-excited motor is a key equipment for the electromechanical energy conversion of the variable-speed pumped-storage power station, and its inductance parameters are important influencing factors for power limit and operation stability, which not only determine the dynamic characteristics of the unit, but also greatly affect the protection setting of the unit.

[0003] In traditional technologies, the calculation method of the inductance parameters of the AC-excited motor is based on the empirical formula of the traditional asynchronous motor. However, when calculating the inductance parameters of the motor in traditional technologies, the calculation accuracy depends on the selection of the empirical coefficient, and the AC-excited motor can operate under a variety of different working conditions. Affected by the motor saturation effect under different operating states, the accuracy of the motor inductance parameters decreases, which is not conducive to improving the accuracy of the motor inductance parameters. Summary of the Invention

[0004] Based on this, in view of the above technical problems, it is necessary to provide a method, device, computer device, computer-readable storage medium, and computer program product for generating inductance parameters of an AC-excited motor under all operating conditions, which can improve the accuracy of the motor inductance parameters.

[0005] In a first aspect, the present application provides a method for generating inductance parameters of an AC-excited motor under all operating conditions, including:

[0006] Construct a sub-domain model and a magnetic network model corresponding to the excitation motor according to the motor structure of the excitation motor; the sub-domain model is used to characterize the relationship between current and magnetic field in the excitation motor; the magnetic network model is used to characterize the relationship between current and magnetic field in the excitation motor;

[0007] Determine the slot current accuracy information according to the stator current information and the rotor current information under the target operating condition. When the slot current accuracy information meets the preset accuracy requirement, determine the magnetic flux density information and the magnetic field strength distribution information of the excitation motor through the sub-domain model and the magnetic network model;

[0008] Determine the inductance parameters of the excitation motor according to the magnetic flux density information and the magnetic field strength distribution information of the excitation motor.

[0009] In one embodiment, constructing the sub-domain model and magnetic network model corresponding to the excitation motor according to the motor structure of the excitation motor includes:

[0010] Determine the stator slot sub-domain, air-gap sub-domain and rotor slot sub-domain of the excitation motor according to the motor structure of the excitation motor, and construct the sub-domain model corresponding to the excitation motor according to the stator slot sub-domain, the air-gap sub-domain and the rotor slot sub-domain;

[0011] Construct a stator core magnetic network according to the motor structure of the excitation motor and the magnetic resistance and connection relationship between the magnetic elements in the stator core of the excitation motor, construct a rotor core magnetic network according to the motor structure of the excitation motor and the magnetic resistance and connection relationship between the magnetic elements in the rotor core of the excitation motor, and determine the magnetic network model corresponding to the excitation motor according to the stator core magnetic network and the rotor core magnetic network.

[0012] In one embodiment, determining the slot current accuracy information according to the stator current information and rotor current information under the target working condition includes:

[0013] Input the stator current information and rotor current information under the target working condition as initial current conditions into the sub-domain model to obtain initial magnetic field information;

[0014] Input the initial magnetic field information into the magnetic network model to obtain first slot current information, input the first slot current information into the sub-domain model, and input the magnetic field information output by the sub-domain model into the magnetic network model to obtain second slot current information;

[0015] Determine the slot current accuracy information according to the difference degree between the first slot current information and the second slot current information.

[0016] In one embodiment, the inductance parameter includes slot leakage inductance information, and determining the inductance parameter of the excitation motor according to the magnetic flux density information and magnetic field intensity distribution information of the excitation motor includes:

[0017] Determine the magnetic field intensity information of the stator slots of the excitation motor according to the magnetic field intensity distribution information of the excitation motor;

[0018] Determine the magnetic field intensity information inside the slots of the stator slots according to the magnetic field intensity information of the stator slots;

[0019] Integrate the magnetic field intensity information inside the slots to obtain the magnetic field energy information inside the slots;

[0020] Determine the slot leakage inductance information of the field excitation motor according to the magnetic field energy information in the slot and the current information in the stator slot.

[0021] In one embodiment, the inductance parameter includes harmonic leakage inductance information. The determining of the inductance parameter of the field excitation motor according to the magnetic flux density information and the magnetic field intensity distribution information of the field excitation motor includes:

[0022] Determine the magnetic flux density information of the air gap of the field excitation motor according to the magnetic flux density information of the field excitation motor;

[0023] Perform Fourier decomposition on the magnetic flux density information of the air gap to obtain a decomposition result;

[0024] Integrate the decomposition result to determine the harmonic leakage inductance information of the field excitation motor.

[0025] In one embodiment, the inductance parameter includes tooth-top leakage inductance information. The determining of the inductance parameter of the field excitation motor according to the magnetic flux density information and the magnetic field intensity distribution information of the field excitation motor includes:

[0026] Determine the magnetic flux density information of the air gap corresponding to the inner diameter of the stator of the field excitation motor and the magnetic flux density information of the air gap corresponding to the outer diameter of the rotor of the field excitation motor according to the magnetic flux density information of the field excitation motor;

[0027] Determine the tooth-top leakage inductance information of the field excitation motor according to the difference between the magnetic flux density information of the air gap corresponding to the inner diameter of the stator of the field excitation motor and the magnetic flux density information of the air gap corresponding to the outer diameter of the rotor of the field excitation motor.

[0028] In one embodiment, the inductance parameter includes end leakage inductance information. The determining of the inductance parameter of the field excitation motor according to the magnetic flux density information and the magnetic field intensity distribution information of the field excitation motor includes:

[0029] Determine the vector magnetic potential information of the field excitation motor according to the magnetic flux density information and the magnetic field intensity distribution information of the field excitation motor;

[0030] Integrate the vector magnetic potential information to determine the end leakage inductance information of the field excitation motor.

[0031] In one embodiment, the inductance parameter includes field excitation inductance information. The determining of the inductance parameter of the field excitation motor according to the magnetic flux density information and the magnetic field intensity distribution information of the field excitation motor includes:

[0032] Determine the magnetic flux density information of the air gap of the field excitation motor according to the magnetic flux density information of the field excitation motor;

[0033] Perform Fourier decomposition on the magnetic flux density information of the air gap to determine the field inductance information of the field excitation motor.

[0034] In a second aspect, the present application also provides an AC field excitation motor inductance parameter generation device under all operating conditions, including:

[0035] A model construction module for constructing a sub-domain model and a magnetic network model corresponding to the field excitation motor according to the motor structure of the field excitation motor; the sub-domain model is used to characterize the relationship between current and magnetic field in the field excitation motor; the magnetic network model is used to characterize the relationship between current and magnetic field in the field excitation motor;

[0036] An information determination module for determining the slot current accuracy information according to the stator current information and the rotor current information under the target operating condition, and determining the magnetic flux density information and the magnetic field strength distribution information of the field excitation motor through the sub-domain model and the magnetic network model when the slot current accuracy information meets the preset accuracy requirement;

[0037] A parameter determination module for determining the inductance parameters of the field excitation motor according to the magnetic flux density information and the magnetic field strength distribution information of the field excitation motor.

[0038] In a third aspect, the present application also provides a computer device. The computer device includes a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the steps of the above method are implemented.

[0039] In a fourth aspect, the present application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by the processor, the steps of the above method are implemented.

[0040] In a fifth aspect, the present application also provides a computer program product. The computer program product includes a computer program, and when the computer program is executed by the processor, the steps of the above method are implemented.

[0041] The above method, device, computer equipment, computer-readable storage medium and computer program product for generating the inductance parameters of an AC excited motor under all operating conditions construct a sub-domain model and a magnetic network model corresponding to the excited motor according to the motor structure of the excited motor; the sub-domain model is used to characterize the relationship between current and magnetic field in the excited motor; the magnetic network model is used to characterize the relationship between current and magnetic field in the excited motor, so as to analyze the motor structure of the excited motor, determine the electromagnetic field relationship between each component and structure in the excited motor, and construct an accurate sub-domain model and magnetic network model; according to the stator current information and rotor current information under the target operating condition, determine the slot current accuracy information, and when the slot current accuracy information meets the preset accuracy requirement, determine the magnetic flux density information and magnetic field strength distribution information of the excited motor through the sub-domain model and the magnetic network model, so as to accurately calculate the magnetic flux density and magnetic field strength distribution of the excited motor based on the sub-domain model and the magnetic network model when the slot current accuracy obtained based on the target operating condition meets the requirement; according to the magnetic flux density information and magnetic field strength distribution information of the excited motor, determine the inductance parameters of the excited motor, so as to accurately calculate the inductance parameters of the excited motor based on the magnetic flux density information and magnetic field strength distribution information of the excited motor, and can analyze the motor structure and electromagnetic field relationship of the excited motor, construct a sub-domain model and a magnetic network model, and based on the sub-domain model and the magnetic network model, analyze the influence of current under different operating conditions on the inductance of the excited motor, and accurately calculate the inductance parameters of the excited motor, thereby improving the accuracy rate of the motor inductance parameters. Description of the Drawings

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments of the present application or related technologies. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0043] Figure 1 It is an application environment diagram of a method for generating the inductance parameters of an AC excited motor under all operating conditions in an embodiment;

[0044] Figure 2 It is a flowchart of a method for generating the inductance parameters of an AC excited motor under all operating conditions in an embodiment;

[0045] Figure 3 It is a schematic diagram of calculating inductance parameters based on a field-circuit coupling model in an embodiment;

[0046] Figure 4 It is a schematic diagram of a sub-domain model in an embodiment;

[0047] Figure 5Schematic diagram of a magnetic network model in an embodiment;

[0048] Figure 6 Schematic diagram of an equivalent circuit of a leakage inductance separation model in an embodiment;

[0049] Figure 7 Schematic diagram of calculating the leakage inductance of the end coil in an embodiment;

[0050] Figure 8 Schematic diagram of the degree of difference between inductance parameters in an embodiment;

[0051] Figure 9 Structural block diagram of a device for generating inductance parameters of an AC-excited motor under all operating conditions in an embodiment;

[0052] Figure 10 Internal structure diagram of a computer device in an embodiment. Detailed implementation manners

[0053] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0054] The method for generating inductance parameters of an AC-excited motor under all operating conditions provided by the embodiments of the present application can be applied to, for example Figure 1In the application environment shown. Among them, the terminal 102 communicates with the server 104 through the network. The data storage system can store the data that the server 104 needs to process. The data storage system can be integrated on the server 104, or can be placed on the cloud or other network servers. The terminal 102 constructs a sub-domain model and a magnetic network model corresponding to the field excitation motor according to the motor structure of the field excitation motor; the sub-domain model is used to characterize the relationship between the current and the magnetic field in the field excitation motor; the magnetic network model is used to characterize the relationship between the current and the magnetic field in the field excitation motor; the terminal 102 determines the slot current accuracy information according to the stator current information and the rotor current information under the target working condition, and when the slot current accuracy information meets the preset accuracy requirement, determines the magnetic flux density information and the magnetic field strength distribution information of the field excitation motor through the sub-domain model and the magnetic network model; the terminal 102 determines the inductance parameters of the field excitation motor according to the magnetic flux density information and the magnetic field strength distribution information of the field excitation motor. Among them, the terminal 102 can be, but is not limited to, various personal computers, laptop computers, smart phones, tablet computers, Internet of Things devices and portable wearable devices. The Internet of Things devices can be smart speakers, smart TVs, smart air conditioners, smart in-vehicle devices, projection devices, etc. The portable wearable devices can be smart watches, smart bracelets, head-mounted devices, etc. The head-mounted devices can be virtual reality (VR) devices, augmented reality (AR) devices, smart glasses, etc. The server 104 can be an independent physical server, or can be a server cluster or distributed system composed of multiple physical servers, or can also be a cloud server providing cloud computing services.

[0055] In an exemplary embodiment, as Figure 2 shown, a method for generating the inductance parameters of an AC field excitation motor under all working conditions is provided. Taking this method applied to the terminal as an example for description, it includes the following steps S202 to step S206. Among them:

[0056] Step S202, construct a sub-domain model and a magnetic network model corresponding to the field excitation motor according to the motor structure of the field excitation motor; the sub-domain model is used to characterize the relationship between the current and the magnetic field in the field excitation motor; the magnetic network model is used to characterize the relationship between the current and the magnetic field in the field excitation motor.

[0057] Among them, the field excitation motor can refer to a motor that controls the operation of the motor by providing a magnetic field through an external power supply.

[0058] Among them, the sub-domain model can refer to the information used to characterize the relationship between the current and the magnetic field in the field excitation motor.

[0059] Among them, the magnetic network model can refer to the information used to characterize the relationship between the current and the magnetic field in the field excitation motor.

[0060] As an example, in order to accurately analyze the inductance parameters of an excitation motor, the terminal can first obtain the motor structure information of the excitation motor and the component information of each component in the excitation motor. After that, the terminal can, according to the preset analysis rules, combine the motor structure of the excitation motor and each component in the excitation motor to analyze the electromagnetic field relationship between each component and the structure in the excitation motor, and construct a sub-domain model and a magnetic network model corresponding to the excitation motor based on the analysis results, so as to use the sub-domain model and the magnetic network model to characterize the relationship between the current and the magnetic field in the excitation motor.

[0061] Step S204: Determine the slot current accuracy information according to the stator current information and the rotor current information under the target operating condition. When the slot current accuracy information meets the preset accuracy requirement, determine the magnetic flux density information and the magnetic field strength distribution information of the excitation motor through the sub-domain model and the magnetic network model.

[0062] Among them, the target operating condition can refer to the information characterizing the operating environment during the operation of the excitation motor and parameters such as the current in the excitation motor.

[0063] Among them, the stator current information can refer to the information characterizing the current flowing through the stator winding in the excitation motor under the target operating condition.

[0064] Among them, the rotor current information can refer to the information characterizing the current flowing through the rotor winding in the excitation motor under the target operating condition.

[0065] Among them, the slot current accuracy information can refer to the information characterizing the accuracy of the current flowing through the conductor (coil) in the stator slot or the rotor slot in the excitation motor. In practical applications, the slot current accuracy information can be determined by the difference between the current values of two slot currents.

[0066] Among them, the magnetic flux density information of the excitation motor can refer to the information characterizing the magnetic flux density in the stator slot, the rotor slot and the air gap in the excitation motor. In practical applications, the magnetic flux density can characterize the strength of the magnetic field.

[0067] Among them, the magnetic field strength distribution information of the excitation motor can refer to the information characterizing the distribution of the magnetic field strength in the stator slot, the rotor slot and the air gap in the excitation motor.

[0068] As an example, the terminal can calculate the slot current information according to the stator current information and the rotor current information under the target operating condition, and determine the slot current accuracy information based on the difference between the slot current information. When the slot current accuracy information meets the preset accuracy requirement, the terminal can input the calculated slot current information into the sub-domain model and the magnetic network model, and then the terminal can calculate the magnetic flux density information and the magnetic field strength distribution information of the excitation motor through the sub-domain model and the magnetic network model.

[0069] Step S206: Determine the inductance parameters of the excitation motor according to the magnetic flux density information and magnetic field intensity distribution information of the excitation motor.

[0070] Among them, the inductance parameters can refer to the information characterizing the relationship between the internal magnetic field and current of the excitation motor. In practical applications, the inductance parameters can include, but are not limited to, the slot leakage inductance of the motor, the harmonic leakage inductance of the motor, the tooth tip leakage inductance of the motor, the end leakage inductance of the motor, and the excitation inductance of the motor, etc.

[0071] As an example, the terminal can calculate parameters such as the slot leakage inductance, harmonic leakage inductance, tooth tip leakage inductance, end leakage inductance, and excitation inductance of the excitation motor by combining the energy method and the magnetic flux linkage method according to the magnetic flux density information and magnetic field intensity distribution information of the excitation motor, so as to obtain the inductance parameters of the excitation motor.

[0072] In the above method for generating the inductance parameters of the AC excitation motor under all working conditions, by constructing a sub-domain model and a magnetic network model corresponding to the excitation motor according to the motor structure of the excitation motor; the sub-domain model is used to characterize the relationship between the current and the magnetic field in the excitation motor; the magnetic network model is used to characterize the relationship between the current and the magnetic field in the excitation motor, so as to analyze the motor structure of the excitation motor, determine the electromagnetic field relationship between each component and structure in the excitation motor, and construct an accurate sub-domain model and magnetic network model; according to the stator current information and rotor current information under the target working condition, determine the slot current accuracy information. When the slot current accuracy information meets the preset accuracy requirements, through the sub-domain model and the magnetic network model, determine the magnetic flux density information and magnetic field intensity distribution information of the excitation motor, so that when the slot current accuracy obtained based on the target working condition meets the requirements, based on the sub-domain model and the magnetic network model, accurately calculate the magnetic flux density and magnetic field intensity distribution of the excitation motor; according to the magnetic flux density information and magnetic field intensity distribution information of the excitation motor, determine the inductance parameters of the excitation motor, so that based on the magnetic flux density information and magnetic field intensity distribution information of the excitation motor, accurately calculate the inductance parameters of the excitation motor, and can analyze the motor structure and electromagnetic field relationship of the excitation motor, construct a sub-domain model and a magnetic network model, and based on the sub-domain model and the magnetic network model, analyze the influence of the current under different working conditions on the inductance of the excitation motor, and accurately calculate the inductance parameters of the excitation motor, thereby improving the accuracy rate of the motor inductance parameters.

[0073] In an exemplary embodiment, according to the motor structure of the excitation motor, a sub-domain model and a magnetic network model corresponding to the excitation motor are constructed, including: determining the stator slot sub-domain, air-gap sub-domain, and rotor slot sub-domain of the excitation motor according to the motor structure of the excitation motor, and constructing a sub-domain model corresponding to the excitation motor according to the stator slot sub-domain, air-gap sub-domain, and rotor slot sub-domain; constructing a stator core magnetic network according to the motor structure of the excitation motor and the magnetic resistance and connection relationship between the magnetic elements in the stator core of the excitation motor, constructing a rotor core magnetic network according to the motor structure of the excitation motor and the magnetic resistance and connection relationship between the magnetic elements in the rotor core of the excitation motor, and determining a magnetic network model corresponding to the excitation motor according to the stator core magnetic network and the rotor core magnetic network.

[0074] Among them, the stator slot sub-domain may refer to the spatial region occupied by the slots on the stator core of the excitation motor and the windings therein.

[0075] Among them, the air-gap sub-domain may refer to the spatial region between the stator and the rotor in the excitation motor.

[0076] Among them, the rotor slot sub-domain may refer to the spatial region occupied by the slots on the rotor core of the excitation motor and the windings therein.

[0077] As an example, the terminal can determine the stator slot sub-domain, air-gap sub-domain, and rotor slot sub-domain of the excitation motor according to the motor structure of the excitation motor. Then, the terminal can use numerical methods (such as the finite element method FEM) to perform electromagnetic field analysis on each sub-domain according to the stator slot sub-domain, air-gap sub-domain, and rotor slot sub-domain to calculate parameters such as magnetic field distribution, magnetic flux density, and magnetic field strength, and construct a sub-domain model corresponding to the excitation motor. The terminal can construct a stator core magnetic network according to the motor structure of the excitation motor and the magnetic resistance and connection relationship between the magnetic elements in the stator core of the excitation motor. The terminal can also construct a rotor core magnetic network according to the motor structure of the excitation motor and the magnetic resistance and connection relationship between the magnetic elements in the rotor core of the excitation motor. After that, the terminal can analyze the magnetic resistance / magnetic conductance of each magnetic network according to the stator core magnetic network and the rotor core magnetic network, and construct a magnetic network model corresponding to the excitation motor.

[0078] In this embodiment, according to the motor structure of the excitation motor, the stator slot sub-domain, air-gap sub-domain, and rotor slot sub-domain of the excitation motor are determined, and a sub-domain model corresponding to the excitation motor is constructed based on the stator slot sub-domain, air-gap sub-domain, and rotor slot sub-domain; according to the motor structure of the excitation motor and the magnetic resistance and connection relationship between the magnetic elements in the stator core of the excitation motor, a stator core magnetic network is constructed, and according to the motor structure of the excitation motor and the magnetic resistance and connection relationship between the magnetic elements in the rotor core of the excitation motor, a rotor core magnetic network is constructed, and a magnetic network model corresponding to the excitation motor is determined based on the stator core magnetic network and the rotor core magnetic network, which can accurately analyze the motor structure of the excitation motor and the magnetic resistance and connection relationship between the components in the excitation motor, construct accurate sub-domain models and magnetic network models, so as to accurately calculate the inductance parameters of the motor based on the sub-domain models and magnetic network models, thereby improving the accuracy rate of the motor inductance parameters.

[0079] In some embodiments, according to the stator current information and rotor current information under the target working condition, the slot current accuracy information is determined, including: taking the stator current information and rotor current information under the target working condition as the initial current conditions and inputting them into the sub-domain model to obtain the initial magnetic field information; inputting the initial magnetic field information into the magnetic network model to obtain the first slot current information, inputting the first slot current information into the sub-domain model, and inputting the magnetic field information output by the sub-domain model into the magnetic network model to obtain the second slot current information; determining the slot current accuracy information according to the difference degree between the first slot current information and the second slot current information.

[0080] Among them, the initial magnetic field information may refer to the information characterizing the magnetic field path and magnetic flux distribution inside the excitation motor.

[0081] Among them, the first slot current information may refer to the information characterizing the current distribution in each slot (such as stator slots, rotor slots, etc.) in the excitation motor when the stator current information and rotor current information under the target working condition are the initial current conditions.

[0082] Among them, the second slot current information may refer to the information characterizing the current distribution in each slot (such as stator slots, rotor slots, etc.) in the excitation motor when the first slot current information is the initial current condition.

[0083] As an example, the terminal can use the stator current information and rotor current information under the target operating condition as the initial current conditions, and input the initial current conditions into the sub-domain model. The sub-domain model can perform electromagnetic field analysis on each sub-domain in the excitation motor based on the initial current conditions through numerical methods (such as the finite element method FEM), determine the magnetic field distribution in each sub-domain of the excitation motor. Then the terminal can convert the magnetic field information of each sub-domain into reluctance and permeance, so as to determine the magnetic field path and magnetic flux distribution inside the excitation motor. The magnetic field path and magnetic flux distribution inside the excitation motor can be used as the initial magnetic field information. Then the terminal can input the initial magnetic field information into the magnetic network model. The magnetic network model can analyze the current distribution in each slot (such as stator slots, rotor slots, etc.) in the excitation motor based on the initial magnetic field information, so as to determine the first slot current information. Then the terminal can use the first slot current information as the initial current condition and input the initial current condition into the sub-domain model. Similarly, the sub-domain model can calculate new magnetic field information based on the current initial current conditions. Then the terminal can input the magnetic field information output by the sub-domain model into the magnetic network model. Similarly, the magnetic network model can determine the second slot current information based on the magnetic field information output by the sub-domain model. Then the terminal can calculate the degree of difference (such as the difference value, etc.) between the first slot current information and the second slot current information to determine the slot current accuracy information. If the slot current accuracy information meets the preset accuracy requirements, the terminal can determine the magnetic flux density information and magnetic field strength distribution information of the excitation motor through the sub-domain model and the magnetic network model; if the slot current accuracy information does not meet the preset accuracy requirements, the terminal can use the second slot current information as the initial current condition and input the initial current condition into the sub-domain model, repeat the above steps, and iteratively calculate new slot current information until the slot current accuracy information calculated based on the new slot current information meets the preset accuracy requirements.

[0084] In this embodiment, by using the stator current information and rotor current information under the target operating condition as the initial current conditions and inputting them into the sub-domain model, the initial magnetic field information is obtained; the initial magnetic field information is input into the magnetic network model to obtain the first slot current information, the first slot current information is input into the sub-domain model, and the magnetic field information output by the sub-domain model is input into the magnetic network model to obtain the second slot current information; according to the degree of difference between the first slot current information and the second slot current information, the slot current accuracy information is determined, which can ensure that the magnetic flux density information and magnetic field strength distribution information of the excitation motor are calculated when the slot current accuracy meets the preset requirements, and improve the accuracy of the magnetic flux density information and magnetic field strength distribution information of the excitation motor.

[0085] In some embodiments, the inductance parameters include slot leakage inductance information. The inductance parameters of the field-excited motor are determined according to the magnetic flux density information and the magnetic field intensity distribution information of the field-excited motor, including: determining the magnetic field intensity information of the stator slots of the field-excited motor according to the magnetic field intensity distribution information of the field-excited motor; determining the magnetic field intensity information inside the stator slots according to the magnetic field intensity information of the stator slots; integrating the magnetic field intensity information inside the slots to obtain the magnetic field energy information inside the slots; and determining the slot leakage inductance information of the field-excited motor according to the magnetic field energy information inside the slots and the current information in the stator slots.

[0086] Among them, the magnetic field intensity information of the stator slots may refer to the information characterizing the average magnetic field intensity of the entire stator slot region.

[0087] Among them, the magnetic field intensity information inside the stator slots may refer to the information characterizing the local magnetic field intensity at a specific position inside the stator slots.

[0088] Among them, the magnetic field energy information inside the slots may refer to the information of the magnetic field energy stored in the windings and iron cores inside the stator slots.

[0089] As an example, the terminal can determine the magnetic field intensity information of the stator slots and the magnetic field intensity information of the rotor slots of the field-excited motor according to the magnetic field intensity distribution information of the field-excited motor. The terminal can determine the magnetic field intensity information inside the stator slots according to the magnetic field intensity information of the stator slots. Then, the terminal can integrate the magnetic field intensity information inside the stator slots to obtain the magnetic field energy information inside the stator slots, and determine the slot leakage inductance information in the stator slots of the field-excited motor according to the magnetic field intensity information inside the stator slots and the current information (such as phase current) in the stator slots. The terminal can also determine the magnetic field intensity information inside the rotor slots according to the magnetic field intensity information of the rotor slots. Then, the terminal can integrate the magnetic field intensity information inside the rotor slots to obtain the magnetic field energy information inside the rotor slots, and determine the slot leakage inductance information in the rotor slots of the field-excited motor according to the magnetic field intensity information inside the rotor slots and the current information (such as phase current) in the rotor slots. In practical applications, the slot leakage inductance information can be obtained by integrating the magnetic field intensity inside the slots calculated based on the sub-domain model and the magnetic network model to obtain the magnetic field energy inside the slots, and further solving the slot leakage inductance information by the energy method. The calculation expression of the slot leakage inductance information can be expressed as:

[0090] .

[0091] Among them, may refer to the slot leakage inductance information, may refer to the magnetic field energy in the bottom region of the motor slots, may refer to the magnetic field energy in the top region of the motor slots, may refer to the magnitude of the phase current.

[0092] In this embodiment, by determining the magnetic field intensity information of the stator slots of the excitation motor according to the magnetic field intensity distribution information of the excitation motor; determining the magnetic field intensity information inside the stator slots according to the magnetic field intensity information of the stator slots; integrating the magnetic field intensity information inside the slots to obtain the magnetic field energy information inside the slots; and determining the slot leakage inductance information of the excitation motor according to the magnetic field energy information inside the slots and the current information in the stator slots, the slot leakage inductance information can be accurately calculated, and the accuracy rate of the slot leakage inductance information can be improved.

[0093] In some embodiments, the inductance parameter includes harmonic leakage inductance information. Determining the inductance parameter of the excitation motor according to the magnetic flux density information and the magnetic field intensity distribution information of the excitation motor includes: determining the magnetic flux density information of the air gap of the excitation motor according to the magnetic flux density information of the excitation motor; performing Fourier decomposition on the magnetic flux density information of the air gap to obtain a decomposition result; and integrating the decomposition result to determine the harmonic leakage inductance information of the excitation motor.

[0094] As an example, the terminal can first determine the magnetic flux density information of the air gap of the excitation motor according to the magnetic flux density information of the excitation motor. After that, the terminal can perform Fourier decomposition processing on the magnetic flux density information of the air gap, then perform integration processing on the decomposition result of the Fourier decomposition, and calculate the harmonic leakage inductance information of the excitation motor through the magnetic flux linkage method. In practical applications, the harmonic leakage inductance information can be obtained by performing Fourier decomposition on the air gap magnetic flux density calculated based on the sub-domain model and the magnetic network model, integrating the harmonic magnetic density part in the decomposition result to obtain the magnetic flux linkage information. After that, the terminal can solve the harmonic leakage inductance information through the magnetic flux linkage method. The calculation expression of the harmonic leakage inductance information can be expressed as:

[0095] .

[0096] where p is the number of pole pairs of the motor, N s is the number of turns of the coil, R rt is the rotor radius, l ef is the effective length of the motor, I s is the magnitude of the phase current of the motor, B sr is the magnetic flux density at the tooth tip of the rotor core, B sr1 is the fundamental wave of the magnetic flux density at the tooth tip of the rotor core. The number of coils included in the A-phase winding is Q A , where the angular range inside the upper and lower sides of the i-th coil is [α il , α iu , and L sδ may refer to the harmonic leakage inductance information.

[0097] In this embodiment, by determining the magnetic flux density information of the air gap of the excitation motor according to the magnetic flux density information of the excitation motor, performing Fourier decomposition on the magnetic flux density information of the air gap to obtain a decomposition result, and integrating the decomposition result to determine the harmonic leakage inductance information of the excitation motor, the harmonic leakage inductance information can be accurately calculated, and the accuracy of the harmonic leakage inductance information can be improved.

[0098] In some embodiments, the inductance parameter includes the tooth-top leakage inductance information. Determining the inductance parameter of the excitation motor according to the magnetic flux density information and the magnetic field intensity distribution information of the excitation motor includes: determining the magnetic flux density information of the air gap corresponding to the inner diameter of the stator of the excitation motor and the magnetic flux density information of the air gap corresponding to the outer diameter of the rotor of the excitation motor according to the magnetic flux density information of the excitation motor; determining the tooth-top leakage inductance information of the excitation motor according to the difference between the magnetic flux density information of the air gap corresponding to the inner diameter of the stator of the excitation motor and the magnetic flux density information of the air gap corresponding to the outer diameter of the rotor of the excitation motor.

[0099] As an example, the terminal can first determine the magnetic flux density information of the air gap corresponding to the inner diameter of the stator of the excitation motor and the magnetic flux density information of the air gap corresponding to the outer diameter of the rotor of the excitation motor according to the magnetic flux density information of the excitation motor. Then, the terminal can calculate the difference between the magnetic flux density information of the air gap corresponding to the inner diameter of the stator of the excitation motor and the magnetic flux density information of the air gap corresponding to the outer diameter of the rotor of the excitation motor. This difference can be used as the tooth-interference leakage magnetic information. Then, the terminal can calculate the tooth-top leakage inductance information of the excitation motor based on the tooth-interference leakage magnetic information according to the magnetic flux linkage method. In practical applications, the tooth-top leakage inductance information can be obtained by calculating the difference in the air-gap magnetic density between the inner diameter of the stator and the outer diameter of the rotor of the two teeth of the motor obtained based on the sub-domain model and the magnetic network model to obtain the tooth-interference leakage magnetic, and further solving the tooth-top leakage inductance information by the magnetic flux linkage method. The calculation expression of the tooth-top leakage inductance information can be expressed as:

[0100] .

[0101] Among them, R st is the inner radius of the stator core of the motor, B st is the air-gap magnetic density of the inner side of the stator core of the motor, B sr is the air-gap magnetic density of the outer side of the rotor core of the motor, and the spatial range corresponding to the i-th tooth-top is [β il , β iu , may refer to the tooth-top leakage inductance information.

[0102] In this embodiment, by determining the magnetic flux density information of the air gap corresponding to the inner diameter of the stator of the excitation motor and the magnetic flux density information of the air gap corresponding to the outer diameter of the rotor of the excitation motor according to the magnetic flux density information of the excitation motor; and determining the tooth-top leakage inductance information of the excitation motor according to the difference between the magnetic flux density information of the air gap corresponding to the inner diameter of the stator of the excitation motor and the magnetic flux density information of the air gap corresponding to the outer diameter of the rotor of the excitation motor, the tooth-top leakage inductance information can be accurately calculated, and the accuracy rate of the tooth-top leakage inductance information can be improved.

[0103] In some embodiments, the inductance parameter includes the end leakage inductance information. Determining the inductance parameter of the excitation motor according to the magnetic flux density information and the magnetic field intensity distribution information of the excitation motor includes: determining the vector magnetic potential information of the excitation motor according to the magnetic flux density information and the magnetic field intensity distribution information of the excitation motor; and integrating the vector magnetic potential information to determine the end leakage inductance information of the excitation motor.

[0104] As an example, the terminal can first determine the vector magnetic potential information of the excitation motor according to the magnetic flux density information and the magnetic field intensity distribution information of the excitation motor. After that, the terminal can integrate the vector magnetic potential information, calculate the magnetic flux linkage information in combination with Stokes' theorem (Stokes theorem), and then the terminal can use the magnetic flux linkage method to calculate the end leakage inductance information of the excitation motor by using the magnetic flux linkage information. In practical applications, the end leakage inductance information can be obtained by numerically integrating the vector magnetic potential of the end winding region calculated based on the sub-domain model and the magnetic network model, solving for the magnetic flux linkage through Stokes' theorem, and further solving for the end leakage inductance information through the magnetic flux linkage method. Taking phase A as the reference phase, when the three-phase windings act together, the end leakage inductance of each phase of the motor satisfies:

[0105] .

[0106] Where, M 1i represents the end mutual leakage inductance between any phase and phase A, i = 1, 2, 3, corresponding to phases A, B, and C respectively, and α i is the electrical angle between the i-th phase winding and the A-phase winding, may refer to the end leakage inductance information.

[0107] In this embodiment, by determining the vector magnetic potential information of the excitation motor according to the magnetic flux density information and the magnetic field intensity distribution information of the excitation motor; and integrating the vector magnetic potential information to determine the end leakage inductance information of the excitation motor, the end leakage inductance information can be accurately calculated, and the accuracy rate of the end leakage inductance information can be improved.

[0108] In some embodiments, the inductance parameter includes field inductance information. According to the magnetic flux density information and magnetic field intensity distribution information of the field excitation motor, the inductance parameter of the field excitation motor is determined, including: determining the magnetic flux density information of the air gap of the field excitation motor according to the magnetic flux density information of the field excitation motor; performing Fourier decomposition on the magnetic flux density information of the air gap to determine the field inductance information of the field excitation motor.

[0109] As an example, the terminal can first determine the magnetic flux density information of the air gap of the field excitation motor according to the magnetic flux density information of the field excitation motor. Then, the terminal can perform Fourier decomposition on the magnetic flux density information of the air gap, and calculate the corresponding magnetic chain information of the fundamental wave component of the air gap magnetic flux density in combination with the decomposition result. Then, the terminal can use the magnetic chain method to calculate the field inductance information of the field excitation motor by using the corresponding magnetic chain information of the fundamental wave component of the air gap magnetic flux density. In practical applications, the field inductance information can be obtained by performing Fourier decomposition on the air gap magnetic flux density calculated based on the sub-domain model and the magnetic network model, solving the corresponding magnetic chain of the fundamental wave component of the air gap magnetic flux density, and further obtaining the field inductance information according to the magnetic chain method. The calculation expression of the field inductance information can be expressed as:

[0110] .

[0111] Where p is the number of pole pairs of the motor, N s is the number of winding turns, R rt is the rotor radius, l ef is the effective length of the motor, I s is the magnitude of the motor phase current, B sr1 is the fundamental wave of the air gap magnetic flux density outside the rotor core of the motor, and L m may refer to the field inductance information.

[0112] In this embodiment, by determining the magnetic flux density information of the air gap of the field excitation motor according to the magnetic flux density information of the field excitation motor; performing Fourier decomposition on the magnetic flux density information of the air gap to determine the field inductance information of the field excitation motor, the field inductance information can be accurately calculated, and the accuracy rate of the field inductance information can be improved.

[0113] In one exemplary embodiment, the calculation method of the inductance parameters of a large AC excited motor is based on the empirical formula of a traditional asynchronous motor. Its calculation accuracy depends on the selection of empirical coefficients. However, there is less manufacturing experience regarding large AC excited motors, making it difficult to select empirical coefficients. Moreover, an AC excited motor can operate under various different working conditions. Affected by the motor saturation effect under different operating states, the variation range of the motor inductance parameters is relatively large, and the error of the inductance parameters obtained by the traditional calculation method is relatively large. Although the calculation method of motor parameters based on three-dimensional finite elements has relatively high calculation accuracy, its calculation time cost is relatively large, and it is not applicable to the comparison and optimal design of a large number of electromagnetic schemes in the initial stage of AC excited motors. Therefore, in order to solve the problem of relatively low calculation accuracy of the inductance parameters of existing large AC excited motors, a method for generating the inductance parameters of an AC excited motor under all working conditions in the early electromagnetic scheme design and optimization stage of the motor is provided. The execution steps of the method for generating the inductance parameters of an AC excited motor under all working conditions may include: The terminal may first establish a field-circuit coupling model of the AC excited motor. The field-circuit coupling model includes an accurate sub-domain model and an equivalent magnetic network model. The accurate sub-domain model includes a stator slot sub-domain, an air-gap sub-domain, and a rotor slot sub-domain. The equivalent magnetic network model includes a stator core magnetic network and a rotor core magnetic network. As Figure 3 shown, a schematic diagram of calculating inductance parameters based on the field-circuit coupling model is provided. Then, the terminal may input the stator and rotor currents under the working conditions required by the motor into the accurate sub-domain model as the initial current conditions of the accurate sub-domain model. The magnetic flux solved by the accurate sub-domain model is input as the initial magnetic field condition of the equivalent magnetic network. The change rate of the slot current before and after is compared with the accuracy requirement, and the obtained slot current is substituted as the current condition of the accurate sub-domain model for iterative calculation until the change rate of the slot current meets the accuracy requirement. The finally obtained slot current is input into the field-circuit coupling model to solve the magnetic flux density and magnetic field strength distribution of the stator and rotor slots and the air gap of the motor. Then, the terminal may calculate the inductance parameters of the motor, such as slot leakage inductance, harmonic leakage inductance, tooth-top leakage inductance, end leakage inductance, and excitation inductance, according to the magnetic field distribution of the AC excited motor obtained by the field-circuit coupling model, and the motor inductance parameters satisfy:

[0114] ,

[0115] ,

[0116] ,

[0117] ,

[0118] ,

[0119] where W ssb and W sstThey are the magnetic field energies at the bottom and top regions of the motor slots respectively, i is the magnitude of the phase current, p is the number of pole pairs of the motor, N s is the number of turns of the stator winding, N r is the number of turns of the rotor winding, R rt is the rotor radius, l ef is the effective length of the motor, I s is the magnitude of the motor phase current, B sr is the magnetic flux density at the tooth tip of the rotor core, B sr1 is the fundamental air-gap magnetic density at the tooth tip of the rotor core, R st is the inner radius of the motor stator core, B st is the air-gap magnetic density inside the motor stator core, B sr is the air-gap magnetic density outside the motor rotor core. M 1i represents the end mutual leakage inductance between any phase and phase A, i = 1, 2, 3, corresponding to phases A, B, and C respectively, α i is the electrical angle between the i-th phase winding and the A-phase winding, is the slot leakage inductance information, is the harmonic leakage inductance information, is the tooth tip leakage inductance information, is the end leakage inductance information, is the field excitation inductance information.

[0120] In this embodiment, through the iterative solution of the motor magnetic field by the field-circuit coupling model, considering the influence of the motor saturation effect on the inductance under different working modes, it is applicable to different working conditions of the motor, and realizes the accurate calculation of the motor inductance parameters under all working conditions.

[0121] In some embodiments, in order to calculate the motor inductance parameters of the field excitation motor, the terminal can first establish a field-circuit coupling model of the motor. The field-circuit coupling model can include an accurate sub-domain model and a magnetic network model, such as Figure 4 shown, a schematic diagram of a sub-domain model is provided, such as Figure 5 shown, a schematic diagram of a magnetic network model is provided. In the accurate sub-domain model of the AC field excitation motor, the stator and rotor slot sub-domains of the motor are source domains, and the effective values of the armature current density and the field excitation current density are J s and J r . The boundary conditions at the bottom and the edges of the slot sub-domain are:

[0122] .

[0123] Among them, θ j , θ i are the central positions of the j / i-th stator and rotor slots respectively.

[0124] The general solution at the bottom of the stator slot is:

[0125] 。

[0126] The general solution of the stator slot top is:

[0127] 。

[0128] The general solution of the air gap is:

[0129] 。

[0130] The general solution of the rotor slot top is:

[0131] 。

[0132] The general solution of the rotor slot bottom is:

[0133] 。

[0134] Among them, A Ib0 -B IIIbν are the undetermined coefficients of the general solution, and β s , β r are the stator and rotor slot angles respectively. l, n, and ν are the harmonic orders of each sub-domain.

[0135] According to the curl theorem, the general solution of the air-gap magnetic flux density in the air-gap sub-domain under the unsaturated condition is:

[0136] ,

[0137] 。

[0138] The general solutions of the radial and tangential magnetic induction intensities in the stator and rotor slot sub-domains are:

[0139] ,

[0140] ,

[0141] ,

[0142] 。

[0143] On the interfaces between different sub-domains, the vector potential and the tangential magnetic field intensity are continuous. The undetermined coefficients of A Ib0 -B IIIbν in each formula are obtained by constructing a matrix equation from the boundary conditions.

[0144] The terminal can establish a simple magnetic network model of the AC excited motor to consider the influence of the motor saturation effect. The radial magnetic flux Φ IIr of the stator tooth is solved by integrating the radial component of the air-gap magnetic flux density:

[0145] 。

[0146] Among them, l ef is the effective length of the motor iron core. The magnetic fluxes Φ Ibr , Φ Ibθ , Φ Itθ at different positions in the stator slots (similarly for the rotor) are respectively:

[0147] ,

[0148] ,

[0149] .

[0150] The terminal can obtain the reluctance distribution of the doubly-fed induction motor through the magnetic circuit model, and then write the node voltage equation based on Kirchhoff's law:

[0151] .

[0152] Among them, A is the branch admittance matrix, and Λ is the permeance distribution.

[0153] Equivalent the saturation effect of the motor to an equivalent current sheet distributed in the slots, then the current inputs of the stator and rotor are (taking the stator side as an example):

[0154] .

[0155] Among them, J sj represents the current density of the jth slot; k is the label of the saturation current sheet; I sj is the current of the jth slot; ΔV is the magnetic potential difference between two nodes in the equivalent magnetic circuit model; Δr is the radius difference between two nodes.

[0156] The terminal can use the initial magnetic flux obtained from the accurate subdomain model as the original magnetic field condition of the equivalent magnetic network model, solve the slot current of the motor as the new current condition and input it into the accurate subdomain model for iterative solution until the change in the obtained slot current reaches the accuracy requirement. The calculation process of the field-circuit coupling model is as Figure 3 shown.

[0157] After solving the internal magnetic field distribution of the motor according to the field-circuit coupling model, separate and solve the leakage inductance and excitation inductance of the AC excited motor. As Figure 6 shown, a schematic diagram of the equivalent circuit of the leakage inductance separation model is provided. The stator and rotor of the large AC excited motor for pumped storage generally do not adopt the skewed slot process, so the skewed slot leakage inductance is not considered. Its leakage inductance includes: slot leakage inductance, harmonic leakage inductance, tooth tip leakage inductance, and end leakage inductance. Taking the solution process of the stator side leakage inductance as an example, the calculation principle is described. The solution process of the rotor side leakage inductance is similar to that of the stator side.

[0158] The motor uses double-layer windings for both the stator and the rotor. Therefore, the energy at the top of the slot W sst and the energy at the bottom of the slot W ssb are integrated and accumulated respectively to obtain the total energy in the slot corresponding to phase A:

[0159] ,

[0160] .

[0161] Among them, Q sab and Q sat represent the slot numbers where the upper and lower windings of phase A are located respectively; l ef is the effective length of the motor. Then the slot leakage inductance L ssσ of each phase of the motor is:

[0162] .

[0163] When the stator is energized alone, the air-gap magnetic density near the outer diameter of the rotor is calculated, the magnetic density waveform is Fourier decomposed, the harmonic content of the air-gap magnetic density is separated, and the harmonic magnetic flux is obtained after integration. Based on the magnetic flux method, the harmonic leakage inductance L sδ is solved:

[0164] ,

[0165] Among them, B sr1 is the fundamental wave component of the air-gap magnetic density; B ic is the magnetic field generated by the induced current in the rotor excitation winding; N s is the number of turns of the winding; I s is the magnitude of the combined current, which is equal to 3i A / 2.

[0166] The air-gap magnetic densities corresponding to the inner diameter of the stator and the outer diameter of the rotor between two adjacent stator teeth are calculated respectively. The leakage magnetic flux between the tooth tips is obtained by taking the difference between the two, and the tooth tip leakage magnetic flux is obtained after integration. Based on the magnetic flux method, the tooth tip leakage inductance L stσ is solved:

[0167] .

[0168] For the end region of the motor, there is no need to solve the vector magnetic potential equation for the vector magnetic potential, and it can be directly calculated through the vector magnetic potential formula. By introducing the mirror image current and the air-gap current, the influence of the magnetization current on the iron core end face and the air-gap is considered respectively, and the end leakage inductance of the AC excited motor is calculated according to the vector magnetic potential.

[0169] Such as Figure 7As shown in the figure, a schematic diagram for calculating the leakage inductance of the end coils is provided. The calculation model of the end leakage inductance of an AC excited motor can be used to calculate the leakage inductance of the end coils. Taking the stator winding as an example, a three-dimensional Cartesian coordinate system of the motor is established. The xy plane coincides with the end face of the motor iron core, the coordinate origin is located at the axis of the motor, and the z axis is perpendicular to the end face of the motor iron core and points outward. After the motor coordinate system is established, the spatial position coordinates of each point of the end winding can be uniquely determined.

[0170] Taking the end winding structure of the motor represented as the broken line ABCDEFGH as an example for illustration, where the current passing through each section of the conductor is expressed as m = 1, 2, …, 7; the mirror current distribution of the end winding current with respect to the iron core end face is the broken line segment A’B’C’D’E’F’G’H’, denoted as m = 8, 9, …, 14; the equivalent air-gap currents AH and HA are denoted as m = 15, 16; the mirror currents of the air-gap currents with respect to the iron core end face A’H’ and H’A’ are denoted as m = 17, 18; the mirror currents A’M’ and H’N’ in the motor slots are denoted as m = 19, 20. The positive directions of each current have been marked in Figure 7 and the current expressions satisfy:

[0171] .

[0172] where, i m is the current value of the m-th section; W is the number of turns of the coil; i is the current value in each turn of the coil; p is the number of pole pairs of the motor; β is the short-pitch ratio.

[0173] Dividing the currents of each section of the No. 1 coil in Figure 7 again, each large section of current is divided into N1 small sections, which are used as the basic units for calculating the vector magnetic potential. Figure 7 The integration path of the vector magnetic potential of the No. 2 coil in Figure 7 is as shown in

[0174] and is divided into 8 large sections, starting from point a and integrating clockwise to form a loop. The 8 large sections on the integration path are also divided into N2 small sections respectively. The more small sections the currents of the No. 1 coil and the integration path of the No. 2 coil are divided into, the higher the calculation accuracy. Figure 7 As shown in 1km , let the current vector of the m-th small section of the k-th large section in the No. 1 coil be l 1km , where the midpoint is P 1kmp , and the coordinate is expressed as (x 1kmp , y 1kmp ); the vector on the integration path of the n-th small section of the g-th large section in the No. 2 coil is l 2gn , where the midpoint is Q 2gn , and its coordinate is expressed as (x 1kmq , y 1kmq , z 1kmq ); the distance R between the two points can be obtained according to the coordinates of the two points in the three-dimensional coordinate system1km2gn Satisfy:

[0175] 。

[0176] According to the vector magnetic potential formula, the current of the m-th small segment in the k-th large segment of the first coil generates a vector magnetic potential A at the midpoint Q of the n-th small segment in the g-th large segment at the end of the second coil 2gn at the point 1km2gn Satisfy:

[0177] 。

[0178] According to the mirror image principle, all media at the end of the motor are equivalent to a uniform air medium at this time, and the direction of the vector magnetic potential A generated by the current element is consistent with the direction of the current element l 1km2gn. direction. Then the vector magnetic potential A generated by all the currents in the first coil at point Q of the second coil 1km is: 2gn at the point 12gn is:

[0179] 。

[0180] Let the number of turns of the second coil be W2. According to Stokes' theorem, the magnetic flux linkage between the first coil current and the turns at the end of the second coil is:

[0181] 。

[0182] The end leakage inductance M between the first coil and the second coil 12 is:

[0183] 。

[0184] Since each coil has two ends, the actual end leakage inductance between the two coils is twice that of M 12 . According to the basic principle of network graph theory, the incidence matrix C of the phase winding and each coil can be written to calculate the end leakage inductance between any two phases:

[0185] 。

[0186] Among them, the values of μ and v are 1, 2, and 3, corresponding to the three phases A, B, and C respectively; C μi , C vj are the corresponding elements in the incidence matrix C; a is the number of parallel branches of the winding.

[0187] Taking phase A as the reference phase, when the three-phase windings act together, the end leakage inductance of each phase of the motor is:

[0188] 。

[0189] where \(i = 1, 2, 3\), corresponding to three phases A, B, and C respectively, and \(\alpha\) i is the electrical angle between the \(i\)-th phase winding and the A-phase winding. Based on the above analysis, the total leakage inductance of the stator is:

[0190] .

[0191] The magnetizing inductance is the inductance corresponding to the magnetic field that generates the effective torque. During the calculation of the harmonic leakage inductance, the fundamental wave component separated at the outer diameter of the rotor is extracted, and then the magnetizing inductance is obtained:

[0192] .

[0193] Taking a 10MW AC-excited motor with 6 poles as an example, the inductance parameters of the motor are calculated respectively based on the method for generating the inductance parameters of the AC-excited motor under full operating conditions and the method of finite element software calculation. As Figure 8 shown, a schematic diagram of the difference degree between inductance parameters is provided. The inductance parameters of the motor calculated based on the method for generating the inductance parameters of the AC-excited motor under full operating conditions are marked as "analysis" in Figure 8 , and the inductance parameters of the motor calculated based on the method of finite element software calculation are marked as "finite element" in Figure 8 . The inductance parameters of the motor calculated based on the method for generating the inductance parameters of the AC-excited motor under full operating conditions have a small difference from the finite element calculation results, with an error within 5%. However, the calculation speed is much faster than that of the finite element software. It is applicable to the comparison and optimization of a large number of electromagnetic schemes in the initial stage of the motor, and can accurately calculate the power limit and dynamic performance of the motor.

[0194] In this embodiment, through the iterative solution of the motor magnetic field by the field-circuit coupling model, the influence of the motor saturation effect on the inductance under different operating modes is considered, which is applicable to different operating conditions of the motor, realizes the accurate calculation of the motor inductance parameters under full operating conditions, solves the problems of large errors in the existing analytical calculation method of the inductance parameters of the AC-excited motor and the inability to consider the inductance change under different operating conditions, and does not require the establishment of a three-dimensional model. The calculation speed is much faster than the finite element method, and it is applicable to the comparison and optimized design of the motor electromagnetic design scheme.

[0195] It should be understood that although the steps in the flowcharts involved in the above-described embodiments are shown in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-described embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same moment, but can be executed at different moments. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or steps or stages in other steps.

[0196] Based on the same inventive concept, an embodiment of the present application further provides a device for generating inductance parameters of an AC-excited motor under all operating conditions for implementing the method for generating inductance parameters of an AC-excited motor under all operating conditions as described above. The solution provided by this device for solving problems is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the device for generating inductance parameters of an AC-excited motor under all operating conditions provided below can refer to the limitations on the method for generating inductance parameters of an AC-excited motor under all operating conditions in the above text, and will not be repeated here.

[0197] In an exemplary embodiment, as Figure 9 shown, a device for generating inductance parameters of an AC-excited motor under all operating conditions is provided, including: a model construction module 902, an information determination module 904, and a parameter determination module 906, where:

[0198] The model construction module 902 is configured to construct a sub-domain model and a magnetic network model corresponding to the excitation motor according to the motor structure of the excitation motor; the sub-domain model is used to characterize the relationship between current and magnetic field in the excitation motor; the magnetic network model is used to characterize the relationship between current and magnetic field in the excitation motor.

[0199] The information determination module 904 is configured to determine slot current accuracy information according to the stator current information and rotor current information under the target operating condition. When the slot current accuracy information meets the preset accuracy requirement, the magnetic flux density information and magnetic field intensity distribution information of the excitation motor are determined through the sub-domain model and the magnetic network model.

[0200] The parameter determination module 906 is configured to determine the inductance parameters of the excitation motor according to the magnetic flux density information and magnetic field intensity distribution information of the excitation motor.

[0201] In one exemplary embodiment, the model construction module 902 is further specifically configured to determine the stator slot sub-domain, air-gap sub-domain, and rotor slot sub-domain of the excitation motor according to the motor structure of the excitation motor, and construct a sub-domain model corresponding to the excitation motor according to the stator slot sub-domain, the air-gap sub-domain, and the rotor slot sub-domain; construct a stator core magnetic network according to the motor structure of the excitation motor and the magnetic resistance and connection relationship between the magnetic elements in the stator core of the excitation motor, construct a rotor core magnetic network according to the motor structure of the excitation motor and the magnetic resistance and connection relationship between the magnetic elements in the rotor core of the excitation motor, and determine a magnetic network model corresponding to the excitation motor according to the stator core magnetic network and the rotor core magnetic network.

[0202] In one exemplary embodiment, the information determination module 904 is further specifically configured to input the stator current information and rotor current information under the target operating condition as initial current conditions into the sub-domain model to obtain initial magnetic field information; input the initial magnetic field information into the magnetic network model to obtain first slot current information, input the first slot current information into the sub-domain model, and input the magnetic field information output by the sub-domain model into the magnetic network model to obtain second slot current information; determine the slot current accuracy information according to the difference degree between the first slot current information and the second slot current information.

[0203] In one exemplary embodiment, the inductance parameter includes slot leakage inductance information, and the parameter determination module 906 is further specifically configured to determine the magnetic field intensity information of the stator slots of the excitation motor according to the magnetic field intensity distribution information of the excitation motor; determine the magnetic field intensity information inside the stator slots according to the magnetic field intensity information of the stator slots; integrate the magnetic field intensity information inside the slots to obtain the magnetic field energy information inside the slots; determine the slot leakage inductance information of the excitation motor according to the magnetic field energy information inside the slots and the current information in the stator slots.

[0204] In one exemplary embodiment, the inductance parameter includes harmonic leakage inductance information, and the parameter determination module 906 is further specifically configured to determine the magnetic flux density information of the air-gap of the excitation motor according to the magnetic flux density information of the excitation motor; perform Fourier decomposition on the magnetic flux density information of the air-gap to obtain a decomposition result; integrate the decomposition result to determine the harmonic leakage inductance information of the excitation motor.

[0205] In one exemplary embodiment, the inductance parameter includes the tooth-top leakage inductance information. Specifically, the parameter determination module 906 is further configured to determine the magnetic flux density information of the air gap corresponding to the inner diameter of the stator of the field excitation motor and the magnetic flux density information of the air gap corresponding to the outer diameter of the rotor of the field excitation motor according to the magnetic flux density information of the field excitation motor; and determine the tooth-top leakage inductance information of the field excitation motor according to the difference between the magnetic flux density information of the air gap corresponding to the inner diameter of the stator of the field excitation motor and the magnetic flux density information of the air gap corresponding to the outer diameter of the rotor of the field excitation motor.

[0206] In one exemplary embodiment, the inductance parameter includes the end leakage inductance information. Specifically, the parameter determination module 906 is further configured to determine the vector magnetic potential information of the field excitation motor according to the magnetic flux density information and the magnetic field intensity distribution information of the field excitation motor; and perform integration on the vector magnetic potential information to determine the end leakage inductance information of the field excitation motor.

[0207] In one exemplary embodiment, the inductance parameter includes the field excitation inductance information. Specifically, the parameter determination module 906 is further configured to determine the magnetic flux density information of the air gap of the field excitation motor according to the magnetic flux density information of the field excitation motor; and perform Fourier decomposition on the magnetic flux density information of the air gap to determine the field excitation inductance information of the field excitation motor.

[0208] Each module in the above AC field excitation motor inductance parameter generation device under all working conditions can be implemented in whole or in part by software, hardware, and their combination. The above modules can be embedded in the processor of the computer device in hardware form or independent of it, or stored in the memory of the computer device in software form, so as to be called by the processor to execute the operations corresponding to the above respective modules.

[0209] In an exemplary embodiment, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as Figure 10As shown in the figure. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit, and an input device. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface, the display unit, and the input device are connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals in a wired or wireless manner, and the wireless manner can be achieved through WIFI, a mobile cellular network, near field communication (NFC), or other technologies. When the computer program is executed by the processor, it implements a method for generating the inductance parameters of an AC-excited motor under all operating conditions. The display unit of the computer device is used to form a visually visible picture, which can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer covered on the display screen, or a button, a trackball, or a touchpad provided on the outer shell of the computer device, or an external keyboard, touchpad, or mouse, etc.

[0210] Those skilled in the art can understand that Figure 10 the structure shown in the figure is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0211] In one embodiment, a computer device is further provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, the steps in the above method embodiments are implemented.

[0212] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by the processor, the steps in the above method embodiments are implemented.

[0213] In one embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by the processor, the steps in the above method embodiments are implemented.

[0214] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0215] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in this application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., and are not limited thereto. The processors involved in the embodiments provided in this application can be general-purpose processors, central processors, graphics processors, digital signal processors, programmable logic devices, data processing logics based on quantum computing, artificial intelligence (AI) processors, etc., and are not limited thereto.

[0216] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this application.

[0217] The above-described embodiments merely represent several implementation manners of this application. The description is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of this application. It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can still be made, and these all belong to the protection scope of this application. Therefore, the protection scope of this application shall be subject to the appended claims.

Claims

1. A method for generating inductance parameters of an AC excitation motor under all working conditions, characterized in that: The method comprises: According to the motor structure of the excitation motor, a subdomain model and a magnetic network model corresponding to the excitation motor are constructed; the subdomain model is used to characterize the relationship between the current and the magnetic field in the excitation motor; the magnetic network model is used to characterize the relationship between the current and the magnetic field in the excitation motor; Determine slot current accuracy information according to stator current information and rotor current information under target working conditions, and determine magnetic flux density information and magnetic field intensity distribution information of the excitation motor through the subdomain model and the magnetic network model when the slot current accuracy information meets preset accuracy requirements; The inductance parameter of the excitation motor is determined according to the magnetic flux density information and the magnetic field strength distribution information of the excitation motor.

2. The method according to claim 1, characterized in that The method of constructing a subdomain model and a magnetic network model corresponding to the excitation motor according to the motor structure of the excitation motor includes: According to the motor structure of the excitation motor, a stator slot subdomain, an air gap subdomain and a rotor slot subdomain of the excitation motor are determined, and a subdomain model corresponding to the excitation motor is constructed according to the stator slot subdomain, the air gap subdomain and the rotor slot subdomain; A stator core magnetic network is constructed according to the motor structure of the excitation motor and the magnetic resistance and connection relationship between each magnetic element in the stator core of the excitation motor. A rotor core magnetic network is constructed according to the motor structure of the excitation motor and the magnetic resistance and connection relationship between each magnetic element in the rotor core of the excitation motor. A magnetic network model corresponding to the excitation motor is determined based on the stator core magnetic network and the rotor core magnetic network.

3. The method according to claim 1, characterized in that The determining of slot current accuracy information according to stator current information and rotor current information under target working conditions includes: Inputting the stator current information and the rotor current information under the target working condition as initial current conditions into the subdomain model to obtain initial magnetic field information; Inputting the initial magnetic field information into the magnetic network model to obtain first slot current information, inputting the first slot current information into the subdomain model, and inputting the magnetic field information output by the subdomain model into the magnetic network model to obtain second slot current information; The slot current accuracy information is determined according to a degree of difference between the first slot current information and the second slot current information.

4. The method according to claim 1, characterized in that: The inductance parameter includes slot leakage inductance information, and determining the inductance parameter of the excitation motor according to the magnetic flux density information and magnetic field intensity distribution information of the excitation motor includes: Determining magnetic field strength information of a stator slot of the excitation motor according to the magnetic field strength distribution information of the excitation motor; Determining the magnetic field strength information within the stator slot according to the magnetic field strength information of the stator slot; Integrating the magnetic field strength information in the slot to obtain magnetic field energy information in the slot; The slot leakage inductance information of the excitation motor is determined according to the magnetic field energy information in the slot and the current information in the stator slot.

5. The method according to claim 1, characterized in that The inductance parameter includes harmonic leakage inductance information, and determining the inductance parameter of the excitation motor according to the magnetic flux density information and the magnetic field intensity distribution information of the excitation motor includes: Determining the magnetic flux density information of the air gap of the excitation motor according to the magnetic flux density information of the excitation motor; Performing Fourier decomposition on the magnetic flux density information of the air gap to obtain a decomposition result; The decomposition result is integrated to determine the harmonic leakage inductance information of the excitation motor.

6. The method according to claim 1, characterized in that The inductance parameter includes tooth tip leakage inductance information, and the inductance parameter of the excitation motor is determined according to the magnetic flux density information and the magnetic field intensity distribution information of the excitation motor, including: Determine, according to the magnetic flux density information of the excitation motor, the magnetic flux density information of the air gap corresponding to the inner diameter of the stator of the excitation motor and the magnetic flux density information of the air gap corresponding to the outer diameter of the rotor of the excitation motor; The tooth tip leakage inductance information of the excitation motor is determined according to the difference between the magnetic flux density information of the air gap corresponding to the inner diameter of the stator of the excitation motor and the magnetic flux density information of the air gap corresponding to the outer diameter of the rotor of the excitation motor.

7. The method according to claim 1, characterized in that The inductance parameter includes end leakage inductance information, and the inductance parameter of the excitation motor is determined according to the magnetic flux density information and the magnetic field intensity distribution information of the excitation motor, including: Determining the vector magnetic potential information of the excitation motor according to the magnetic flux density information and the magnetic field strength distribution information of the excitation motor; The vector magnetic potential information is integrated to determine the end leakage inductance information of the excitation motor.

8. The method according to claim 1, characterized in that The inductance parameter includes excitation inductance information, and the inductance parameter of the excitation motor is determined according to the magnetic flux density information and the magnetic field intensity distribution information of the excitation motor, including: Determining the magnetic flux density information of the air gap of the excitation motor according to the magnetic flux density information of the excitation motor; The magnetic flux density information of the air gap is subjected to Fourier decomposition to determine the excitation inductance information of the excitation motor.

9. A device for generating inductance parameters of an AC excitation motor under all working conditions, characterized in that: The device comprises: A model building module, for building a subdomain model and a magnetic network model corresponding to the excitation motor according to the motor structure of the excitation motor; the subdomain model is used to characterize the relationship between the current and the magnetic field in the excitation motor; the magnetic network model is used to characterize the relationship between the current and the magnetic field in the excitation motor; An information determination module, used to determine slot current accuracy information according to stator current information and rotor current information under target working conditions, and to determine magnetic flux density information and magnetic field intensity distribution information of the excitation motor through the subdomain model and the magnetic network model when the slot current accuracy information meets the preset accuracy requirement; The parameter determination module is used to determine the inductance parameter of the excitation motor according to the magnetic flux density information and the magnetic field intensity distribution information of the excitation motor.

10. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 8 are implemented.

Images