Cross transformer vector control method, controller and system for asynchronous motor test platform

Abstract

This invention discloses a cross-transformer vector control method, controller, and system for an asynchronous motor test platform, belonging to the field of motor testing technology. It includes: constructing an equivalent virtual DC bus voltage on the motor side based on the configuration parameters of the frequency converter and transformer; converting the original sampled current into an equivalent current on the motor side based on the sampling location; determining a fixed phase shift angle based on the transformer connection group and performing rotational compensation on the equivalent current on the motor side; inputting the compensated current into the vector control link for flux linkage observation, speed observation, and current adjustment to obtain a voltage command; superimposing the voltage command with the fixed phase shift angle to obtain a reconstructed voltage command; and normalizing and modulating the reconstructed voltage command based on the equivalent virtual DC bus voltage to generate the frequency converter output modulation quantity. This invention systematically integrates the equivalent transformer relationship into the vector control link, enabling the same frequency converter to stably drive asynchronous motors of different voltage levels via a transformer, thus improving the versatility and control accuracy of the test platform.

Description

Technical Field

[0001] This invention relates to the field of motor testing technology, and specifically to a cross-transformer vector control method, controller, and system for an asynchronous motor test platform. Background Technology

[0002] In the process of motor production and testing, test platforms typically need to cover asynchronous motors of various voltage levels, such as 380V, 690V, 1140V, 3kV, and 3.3kV. Existing test solutions generally configure corresponding frequency converters, power supplies, or step-up / step-down devices based on the rated voltage level of the motor under test. For low-voltage motors, low-voltage frequency converters are usually configured for direct drive; for medium- and high-voltage motors, high-voltage frequency converters, dedicated test power supplies, or voltage adaptation via transformers may be used. This type of solution can meet the testing needs of motors of a single or a few voltage levels. However, when the same test platform needs to frequently switch between motors of different voltage levels and capacities, multiple sets of drive devices of different voltage levels need to be configured, or external step-up / step-down wiring needs to be frequently adjusted. This results in high equipment investment, complex on-site wiring, long test preparation time, and difficulty in unifying control parameters, protection parameters, and debugging methods between different devices.

[0003] To improve the versatility of the test platform, a feasible solution is to use a high-voltage frequency converter output followed by a step-down transformer to adapt to asynchronous motors of different voltage levels. This solution, in terms of hardware, utilizes the high-voltage frequency converter and transformer to achieve voltage level conversion, thereby reducing the need for multiple frequency converter configurations. For example, the output of a high-voltage frequency converter (e.g., 10kV) can be converted to the voltage level required by the tested motor via a step-down transformer (e.g., 10kV / 380V, 10kV / 690V, etc.). However, when using vector control to drive an asynchronous motor, the transformer is not a simple voltage converter. The transformer introduces variations in the voltage and current amplitude ratios, and different wiring groups (e.g., Dyn11, Yd11, etc.) introduce fixed phase offsets; simultaneously, the sampling locations for current and voltage may be on the primary or secondary side of the transformer. These factors can lead to inconsistencies in amplitude and phase between the sampled electrical quantities on the frequency converter side, the actual electrical quantities of the motor on the transformer secondary side, and the electrical angle, flux linkage observations, and modulation references used internally by the vector control algorithm.

[0004] Therefore, if the high-voltage frequency converter is directly connected to the asynchronous motor via a step-down transformer, issues such as current feedback not matching the actual motor current and flux linkage observation angle deviation may occur. Inaccurate shaft decoupling and inconsistencies between the output voltage command and the actual voltage reference at the motor terminals affect the stability and accuracy of vector control. Existing solutions typically focus more on the hardware voltage adaptation function of the transformer, making it difficult to conveniently adapt to asynchronous motor tests with a wide range of voltage levels on the same high-voltage frequency converter platform. Summary of the Invention

[0005] The purpose of this invention is to provide a cross-transformer vector control method, controller, and system for an asynchronous motor test platform, in order to solve the technical problem in the prior art where the amplitude change and phase shift introduced by the transformer lead to inconsistent vector control reference systems, making it difficult to adapt asynchronous motors with a wide range of voltage levels to the same frequency converter platform.

[0006] This invention is achieved through the following technical solution:

[0007] In a first aspect, the present invention provides a cross-transformer vector control method for an asynchronous motor test platform, the asynchronous motor test platform comprising a frequency converter, a transformer, and an asynchronous motor under test connected in sequence; the method includes:

[0008] Based on the configuration parameters of the frequency converter and transformer, an equivalent virtual DC bus voltage is constructed on the motor side;

[0009] Based on the sampling location of the original sampling current, the original sampling current is converted into an equivalent current on the motor side, wherein the sampling location is the primary side or the secondary side of the transformer;

[0010] The fixed phase shift angle is determined according to the connection group of the transformer, and the equivalent current on the motor side is rotated and compensated based on the fixed phase shift angle to obtain the compensated current.

[0011] The compensated current is input into the asynchronous motor vector control link to perform flux linkage observation, speed observation and current regulation based on the equivalent reference frame on the motor side, and obtain voltage commands.

[0012] The voltage command is superimposed with the fixed phase shift angle to obtain the reconstructed voltage command in the stationary coordinate system;

[0013] The reconstructed voltage command is normalized and modulated based on the equivalent virtual DC bus voltage to obtain a modulation amount for controlling the output of the frequency converter, and then output to the frequency converter.

[0014] The control method of this invention embeds a transformer equivalent control layer into the vector control link, unifying the transformer ratio and connection group phase shift into the control link: amplitude conversion and phase compensation are performed before current feedback enters vector control, ensuring that flux linkage observation and current regulation are based on the actual motor-side current; phase reconstruction is performed after the output voltage command, ensuring that the inverter output voltage, after passing through the transformer, is in phase with the voltage required by the motor; simultaneously, an equivalent virtual DC bus voltage on the motor side is constructed to ensure that the modulation reference matches the motor-side voltage level. Through these means, this invention enables sampling, flux linkage observation, current regulation, and modulation output to all operate under a unified motor-side equivalent reference system, effectively eliminating the influence of amplitude changes and phase shifts introduced by the transformer on vector control. This allows the same inverter to stably drive asynchronous motors of different voltage levels via a transformer, improving the versatility and control accuracy of the test platform.

[0015] In some implementations, the original sampled current is converted into an equivalent current on the motor side based on the sampling location of the original sampled current, including:

[0016] If the sampling location is the primary side of the transformer, the original sampling current is converted into the equivalent current on the secondary side according to the transformer's turns ratio parameters, and used as the equivalent current on the motor side.

[0017] If the sampling location is the secondary side of the transformer, the original sampled current is directly used as the equivalent current on the motor side.

[0018] In some implementations, an equivalent virtual DC bus voltage on the motor side is constructed based on the configuration parameters of the frequency converter and transformer, including:

[0019] Calculate the total DC voltage of the frequency converter based on the number of series power units in each phase of the frequency converter and the DC voltage of a single power unit;

[0020] Multiplying the total DC voltage by the voltage equivalence factor of the transformer yields the equivalent virtual DC bus voltage on the motor side.

[0021] In some implementations, determining the fixed phase shift angle based on the transformer's connection group includes: querying the fixed phase shift angle corresponding to the transformer's connection group based on a preset mapping relationship between connection groups and fixed phase shift angles;

[0022] The mapping relationship between the transformer's connection group and the fixed phase shift angle is as follows:

[0023] ;

[0024] in, Indicates the connection group of the step-down transformer. A fixed phase shift angle; This represents the mapping function; for non-phase shift connection groups, Pick For those with The wiring group of phase shift, According to the corresponding connection method degree or Spend.

[0025] In some implementations, rotational compensation is performed on the equivalent current on the motor side based on the fixed phase shift angle to obtain the compensated current, including:

[0026] The rotation compensation matrix is ​​determined based on the fixed phase shift angle;

[0027] Obtain the components of the equivalent current on the motor side in the stationary coordinate system, and use the rotation compensation matrix to perform rotation compensation on each component to obtain the compensated current components.

[0028] The compensated current is obtained based on the compensated current components.

[0029] In some implementations, the rotation compensation matrix is ​​represented as:

[0030] ;

[0031] in, This indicates the fixed phase shift angle determined by the wiring group.

[0032] In some implementations, the voltage command is superimposed with the fixed phase shift angle to obtain a reconstructed voltage command in a stationary coordinate system, including:

[0033] Obtain the motor-side electrical angle of the asynchronous motor vector control link. The fixed phase shift angle ;

[0034] The electric angle of the motor side Superimposed fixed phase shift angle To obtain the reconstruction angle ;

[0035] Regarding the reconstructed angle Perform an inverse Park transformation to obtain the reconstructed voltage command in the stationary coordinate system.

[0036] In a second aspect, the present invention provides a controller, comprising:

[0037] One or more processors;

[0038] Storage device for storing one or more programs;

[0039] When the one or more programs are executed by the one or more processors, the one or more processors implement the cross-transformer vector control method for an asynchronous motor test platform as described in any one of the first aspects of the present invention.

[0040] Thirdly, the present invention provides an asynchronous motor testing system, comprising:

[0041] The frequency converter, wherein the primary side of the frequency converter is connected to the power grid or test power supply;

[0042] A transformer, the primary side of which is connected to the secondary side of the frequency converter, and the secondary side of which is connected to the asynchronous motor under test;

[0043] A current sampling device, located on the primary or secondary side of the transformer, is used to sample the current;

[0044] The controller, connected to the current sampling device, frequency converter, and transformer, is used to execute the cross-transformer vector control method for an asynchronous motor test platform as described in any one of the first aspects of the present invention.

[0045] In some implementations, the frequency converter is a high-voltage frequency converter, and the transformer is a low-voltage transformer.

[0046] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0047] 1. This invention incorporates transformer turns ratio, connection group phase shift, and sampling position into the control link through transformer equivalent control in the asynchronous motor vector control link. This ensures that sampling, coordinate transformation, flux linkage observation, current regulation, and modulation output all operate under a unified equivalent reference system on the motor side. This effectively solves the problem of inconsistent vector control reference systems caused by amplitude changes and phase shifts introduced by the transformer, enabling the same frequency converter to drive asynchronous motors of different voltage levels via a transformer.

[0048] 2. This invention supports two sampling methods based on the sampling location: primary side sampling conversion and secondary side sampling of the transformer. It can adapt to the hardware sampling layout of different test platforms and has good platform adaptability.

[0049] 3. This invention embeds transformer connection group phase shift compensation into the complete link of sampling, coordinate transformation, flux linkage observation, current regulation and output reconstruction. Compared with the method of only performing fixed angle correction at the output end, it can more comprehensively eliminate reference system deviation and improve the control accuracy of flux linkage observation and current closed loop.

[0050] 4. By constructing an equivalent virtual DC bus voltage on the motor side, this invention enables the DC voltage of the inverter unit, the number of series stages, and the transformer turns ratio to jointly participate in output voltage limiting and modulation normalization, thereby improving the parameter consistency and control reliability of wide voltage level tests.

[0051] 5. This invention can reduce the need for configuring independent frequency converters for different motor voltage levels, and reduce the number of test platform equipment, wiring and switching complexity, and on-site debugging costs. Attached Figure Description

[0052] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0053] Figure 1 This is a schematic diagram of the topology of a wide voltage level motor test platform according to an embodiment of the present invention;

[0054] Figure 2 This is a flowchart of a cross-transformer vector control method for an asynchronous motor test platform according to an embodiment of the present invention;

[0055] Figure 3 This is a schematic diagram of transformer amplitude equivalence and connection group phase compensation according to an embodiment of the present invention;

[0056] Figure 4 This is a schematic diagram of a cross-transformer closed-loop vector control method according to an embodiment of the present invention;

[0057] Figure 5 This is a schematic diagram of an asynchronous motor testing system according to an embodiment of the present invention;

[0058] Figure 6 This is a schematic diagram of the module structure of a cross-transformer vector control system according to an embodiment of the present invention;

[0059] Figure 7 This is a schematic diagram illustrating the fusion of a transformer equivalent control layer and a vector control link according to an embodiment of the present invention. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0061] When using a high-voltage frequency converter to drive asynchronous motors of different voltage levels via a step-down transformer in a motor test platform, the transformer introduces proportional changes in voltage and current amplitudes and a fixed phase offset. If the inverter-side electrical quantities are directly used as motor-side electrical quantities according to the traditional vector control method, it will lead to problems in flux linkage observation, synchronous speed observation, and... There are phase and amplitude deviations between current regulation and output modulation reconstruction, which affect the stability of closed-loop vector control.

[0062] In view of this, embodiments of the present invention provide a cross-transformer vector control method, controller, and system for an asynchronous motor test platform to solve the above-mentioned problems. The control method of the present invention is as follows: a transformer equivalent control layer is set in the asynchronous motor vector control link of the controller, unifying the transformer ratio, connection group phase shift, and sampling position into the control link. Through equivalent sampling current on the motor side, connection group phase shift compensation, equivalent virtual DC bus on the motor side, and output angle reconstruction, sampling, coordinate transformation, flux linkage observation, current regulation, and modulation output all operate under a unified equivalent reference system on the motor side. The method proposed in this invention can effectively eliminate the influence of amplitude and phase deviations introduced by the transformer on vector control, enabling the same high-voltage frequency converter to be adapted to asynchronous motors of different voltage levels such as 380V, 690V, 1140V, 3kV, and 3.3kV via a step-down transformer, making it suitable for wide-voltage-level motor test platforms.

[0063] The technical solutions provided by the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0064] The control method of this invention is applied to an asynchronous motor test platform; please refer to [link / reference]. Figure 1 , Figure 1 A structural diagram of a test platform for asynchronous motors is shown, comprising a frequency converter, a transformer, and an asynchronous motor under test connected in sequence. Figure 1 In the example, the frequency converter is a high-voltage frequency converter and the transformer is a low-voltage transformer, forming a drive architecture of "high-voltage frequency converter + step-down transformer".

[0065] The cross-transformer vector control method of this invention is executed by a controller, which has signal connections to the frequency converter, the transformer, and the asynchronous motor under test. The controller is connected to a current sampling device via signal lines to receive current sampling signals from the primary or secondary side of the transformer. The controller is also connected to the frequency converter via signal lines to send pulse width modulation (PWM) drive signals to control the switching of the frequency converter's power switching devices, and simultaneously receives operating status signals (such as DC bus voltage and power unit status) fed back from the frequency converter. The controller is connected to the transformer via signal lines to receive the transformer's configuration parameters (such as turns ratio and connection group). These parameters can be pre-input by the operator through the controller's human-machine interface or obtained by reading the parameter storage module built into the transformer. Finally, the controller is connected to the asynchronous motor under test via signal lines to receive the motor's speed feedback signals (such as speed signals from an encoder or rotary transformer) for speed closed-loop control.

[0066] The controller, as the core of the entire control system, executes the cross-transformer vector control method of this invention. First, the controller acquires the configuration parameters of the frequency converter and the transformer, as well as the current sampling location. The configuration parameters of the frequency converter include at least the number of series power units (or equivalent units) per phase and the DC voltage of a single power unit; the configuration parameters of the transformer include at least the transformer's turns ratio and connection group.

[0067] The above configuration parameters can be obtained from the controller through one or a combination of the following methods:

[0068] (1) Human-machine interface input: Operators can manually input parameters such as the number of series power units per phase of the frequency converter, the DC voltage of a single power unit, the transformer ratio, the wiring group, and the current sampling position through the touch screen, host computer software, or handheld programmer equipped on the controller. The input parameters are stored in the controller's non-volatile memory unit and are not lost after power failure.

[0069] (2) Automatic parameter identification: The controller reads the rated parameters and operating parameters of the frequency converter through the communication bus (such as CAN bus, Modbus, Profibus, etc.) between the controller and the frequency converter; and reads the rated ratio, wiring group and other factory parameters of the transformer through communication with the parameter storage module built into the transformer (such as electronic tag, EEPROM, etc.).

[0070] (3) DIP switch or hardware jumper settings: For some parameters, hardware-level configuration can be performed through DIP switches or jumper caps on the controller hardware board. The controller reads these hardware settings during power-on initialization.

[0071] (4) Remote configuration: The controller is connected to the upper management system via Ethernet, 4G / 5G and other communication methods, and the configuration parameters are sent by the remote server.

[0072] In a preferred embodiment of the present invention, the controller first reads the configuration parameters stored in the non-volatile memory during each power-on initialization. If the parameters are valid, they are used directly; if the parameters are missing or invalid, the operator is prompted to input them through the human-machine interface, and the input parameters are saved to the non-volatile memory. The current sampling position refers to the installation location of the current sampling device in the circuit, which can be located on the primary side of the transformer (i.e., the inverter output side, transformer input terminal) or on the secondary side of the transformer (i.e., the transformer output side, motor input side).

[0073] The current sampling device is used to collect the current output from the frequency converter to the transformer or the current output from the transformer to the motor. Specifically, the current sampling device includes a current sensor and a signal conditioning circuit. The current sensor can be a Hall-effect current sensor or a current transformer (CT), preferably a closed-loop Hall current sensor, which features fast response, good linearity, and high measurement accuracy. The signal conditioning circuit includes an amplifier circuit, a filter circuit, and an analog-to-digital converter circuit, used to amplify and filter (eliminate high-frequency noise) the analog signal output from the sensor and convert it into a digital signal for the controller's digital signal processor (DSP) to read.

[0074] The current sampling device collects the instantaneous value of the three-phase AC current on the output side of the frequency converter or the output side of the transformer. , , The instantaneous current values ​​are then converted from analog to digital and input to the controller. The controller uses these instantaneous current values ​​to perform the coordinate transformations (Clarke transformation and Park transformation) required for vector control, thereby achieving closed-loop current regulation.

[0075] See Figure 2 As shown, based on the above configuration parameters, the controller executes the following closed-loop control steps:

[0076] S101, based on the configuration parameters of the frequency converter and transformer, constructs the equivalent virtual DC bus voltage on the motor side.

[0077] The controller constructs an equivalent virtual DC bus voltage on the motor side based on the DC voltage of the power unit of the high-voltage frequency converter, the number of series unit stages, and the transformer voltage equivalence coefficient.

[0078] Specifically, the equivalent virtual DC bus voltage on the motor side can be expressed as:

[0079]

[0080] in, This represents the equivalent virtual DC bus voltage on the motor side. This indicates the number of series power unit stages or equivalent stages per phase of the frequency converter. This represents the DC voltage of a single power unit. This represents the voltage equivalent coefficient determined by the transformer turns ratio.

[0081] This equivalent virtual DC bus voltage will be used for normalization processing in the subsequent modulation process, so that the modulation reference matches the motor-side voltage level, ensuring that the output voltage command can be correctly mapped to the actual output of the frequency converter.

[0082] S102 converts the original sampled current into an equivalent current on the motor side based on the sampling location of the original sampled current.

[0083] The controller uses different methods to obtain the equivalent current on the motor side depending on the location of the current sampling point.

[0084] If the current sampling point is located on the primary side of the transformer (output side of the frequency converter), the controller converts the primary side sampling current into the equivalent current of the secondary side of the transformer and the motor input side according to the transformer current equivalence coefficient and the phase shift angle of the wiring group.

[0085] Specifically, the amplitude is first calculated based on the transformer current equivalence factor:

[0086]

[0087] in, This represents the current equivalent coefficient determined by the transformer turns ratio. This represents the current vector obtained by sampling from the primary side of the transformer. This represents the equivalent current vector on the motor side after amplitude conversion.

[0088] If the current sampling point is located on the secondary side of the transformer (motor input side), then the secondary side sampling current is directly used as the equivalent current on the motor side.

[0089]

[0090] in, This represents the current vector obtained by sampling from the secondary side of the transformer. This represents the equivalent current vector on the motor side that participates in vector control.

[0091] By using equivalent current conversion, the controller can obtain accurate equivalent current on the motor side, regardless of whether the current sampling point is located on the primary or secondary side of the transformer, thus adapting to the hardware sampling layout of different test platforms.

[0092] S103 determines the fixed phase shift angle according to the transformer's connection group, and performs rotational compensation on the equivalent current on the motor side based on the fixed phase shift angle to obtain the compensated current.

[0093] The controller determines the fixed phase shift angle based on the transformer's wiring group. Specifically, based on the preset mapping relationship between the wiring group and the fixed phase shift angle, the fixed phase shift angle corresponding to the transformer's wiring group is queried:

[0094]

[0095] in, Indicates the transformer's connection group A fixed phase shift angle is determined. This represents the mapping function between the wiring group and the fixed phase shift angle. For wiring groups without phase shift (such as Yy0, Dd0, etc.) Set to 0; for wiring groups with a 30-degree phase shift (such as Dyn11, Yd11, etc.). Choose +30 degrees or -30 degrees according to the corresponding connection method.

[0096] Understandably, for other wiring groups with different phase shifts, The corresponding positive or negative angle is selected accordingly.

[0097] Then, the controller performs rotational compensation on the equivalent current on the motor side based on the transformer's fixed phase shift angle. Specifically, the converted current is transformed to... A stationary coordinate system is used, and rotational compensation is performed based on the phase shift angle of the transformer connection group:

[0098]

[0099] in,

[0100] In the formula, , This represents the current component in the stationary coordinate system before compensation. , This represents the current component in the equivalent stationary coordinate system on the motor side after compensation. Indicates the phase shift angle by the wiring group. A defined rotation compensation matrix.

[0101] With this compensation, subsequent flux linkage observation, current regulation, and output reconstruction are all based on the equivalent reference frame on the motor side, eliminating the phase offset introduced by the transformer connection group.

[0102] S104 inputs the compensated current into the asynchronous motor vector control link to perform flux linkage observation, speed observation and current regulation based on the equivalent reference frame on the motor side, and obtains voltage commands.

[0103] The controller uses the compensated equivalent motor current as the current feedback input and sends it to the asynchronous motor vector control link. The asynchronous motor vector control link performs flux linkage observation, speed observation, and current closed-loop regulation based on the motor-side equivalent reference frame, and outputs... Shaft voltage command ( , Since the current input to the vector control link has already undergone amplitude reduction and phase compensation, the flux observer "sees" the actual motor-side current, thus ensuring the accuracy of flux observation, speed observation, and current regulation.

[0104] In this implementation, the asynchronous motor vector control link is integrated into the controller, serving as a functional module or software algorithm unit within the controller. This vector control link itself employs a well-known asynchronous motor vector control algorithm (Field Oriented Control, FOC), also known as field-oriented control.

[0105] Specifically, the basic principle of the asynchronous motor vector control link is: to transform the stator current of the asynchronous motor in the three-phase stationary coordinate system through coordinate transformation. , , Transformed into a two-phase rotating coordinate system Excitation components in coordinate system ( ) and torque component ( This achieves decoupled control similar to that of a DC motor. Its basic control flow includes:

[0106] (1) Current feedback processing: The compensated equivalent current on the motor side (the amplitude conversion and phase compensation have been completed in the transformer equivalent control layer) is used as the current feedback signal. The three-phase current is transformed into a two-phase stationary coordinate system through Clarke transformation (3 / 2 transformation). The components in the coordinate system are then transformed using the Park transformation (rotation transformation). Component transformation Rotating coordinate system , Feedback value.

[0107] (2) Flux flux observation: Based on the mathematical model of the motor (voltage equation and flux flux equation), using the stator voltage, current and speed information, the amplitude and phase of the rotor flux flux are estimated by a flux flux observer (such as voltage model method, current model method or combined model method), and the rotor flux flux angle is obtained. (i.e., the electrical angle on the motor side).

[0108] (3) Speed ​​observation and closed loop: The motor speed is estimated based on the flux observation results, compared with the given speed, and the torque current command is output through the speed regulator (PI regulator). .

[0109] (4) Current closed-loop regulation: (Excitation current command, typically set to a given value corresponding to the rotor flux linkage) and (Torque current command) respectively with , Feedback value comparison, output through current regulator (PI regulator) Shaft voltage command , .

[0110] S105 superimposes the voltage command with a fixed phase shift angle to obtain the reconstructed voltage command in the stationary coordinate system.

[0111] The controller obtains the motor-side electrical angle of the asynchronous motor vector control link. The electric angle of the motor side Superimposed fixed phase shift angle The output reconstruction angle is obtained as follows:

[0112]

[0113] Based on the output reconstruction perspective For voltage commands ( , Perform an inverse Park transformation to obtain the voltage command in the stationary coordinate system:

[0114]

[0115]

[0116] This step compensates for the transformer phase shift angle during output reconstruction, ensuring that the voltage vector actually output by the frequency converter is in phase with the voltage vector required by the motor side after passing through the transformer.

[0117] S106 normalizes the reconfigured voltage command based on the equivalent virtual DC bus voltage to obtain the modulation amount used to control the inverter output, and outputs it to the inverter.

[0118] The controller is based on the equivalent virtual DC bus voltage on the motor side. Perform normalized modulation:

[0119]

[0120]

[0121] in, , This is the normalized modulation amount. The controller generates drive signals for the inverter's power switching devices based on the normalized modulation amount, and controls the inverter to output the corresponding voltage.

[0122] Thus, the entire control process forms a complete closed loop: from current sampling, amplitude conversion, phase compensation, vector control calculation to output reconstruction and normalized modulation, all links are based on a unified equivalent reference system on the motor side, eliminating the amplitude and phase deviations introduced by the transformer.

[0123] In existing technologies, vector control methods directly input the sampled current from the inverter side as the current feedback signal into the vector control link. However, this invention adds a transformer equivalent control layer before the current feedback signal enters the vector control link. This layer performs amplitude conversion (based on the transformer turns ratio) and phase compensation (based on the transformer connection group) on the sampled current, ensuring that the current input to the vector control link is the equivalent current from the motor side—that is, a current signal whose amplitude and phase are consistent with the actual motor current. Simultaneously, at the output of the vector control link… Following the shaft voltage command, this invention also performs phase compensation for the electrical angle in the output reconstruction stage and normalizes it using the equivalent virtual DC bus voltage on the motor side in the modulation stage. Therefore, the vector control link of this invention can itself adopt existing technology, but by adding transformer equivalent processing stages before and after it, "cross-transformer" vector control is achieved, enabling the same high-voltage frequency converter to stably drive asynchronous motors of different voltage levels through a step-down transformer.

[0124] In some specific implementations, the controller is configured to convert the original sampled current into an equivalent current on the motor side based on the sampling location of the original sampled current, as follows:

[0125] (i) If the sampling location is the primary side of the transformer (i.e., the output side of the frequency converter and the input end of the transformer), the controller will convert the original sampling current into the equivalent current of the secondary side according to the transformer turns ratio parameters, and use it as the equivalent current of the motor side.

[0126] Specifically, let the transformer turns ratio be... (The ratio of primary voltage to secondary voltage), then the current equivalent coefficient Primary side sampling current Multiply by the current equivalent factor The equivalent current on the secondary side is obtained. The equivalent current on the secondary side is the equivalent current on the motor side.

[0127] (ii) If the sampling location is the secondary side of the transformer (i.e., the transformer output side and the motor input terminal), the controller directly uses the original sampled current as the equivalent current on the motor side. Its amplitude is already consistent with the actual current on the motor side, and there is no need to perform amplitude conversion.

[0128] This setup allows the same control method to adapt to different current sampling arrangements. In practical engineering, the current sampling device on some test platforms may be installed on the inverter output side (transformer primary side), while others may be installed between the transformer and the motor (transformer secondary side). This solution adaptively selects the current acquisition method based on the sampling location, supporting primary side sampling conversion and secondary side direct sampling without requiring changes to the hardware layout.

[0129] In some specific implementations, in step S101, the method for constructing the equivalent virtual DC bus voltage on the motor side based on the configuration parameters of the frequency converter and transformer is as follows:

[0130] First, the controller obtains the number of series power unit stages (or equivalent stages) per phase of the frequency converter. and the DC voltage of a single power unit .

[0131] For a unit-series multilevel high-voltage frequency converter, each phase consists of multiple power units connected in series, and each power unit has an independent DC bus. Therefore, the total DC voltage of the frequency converter... for:

[0132]

[0133] Then, the controller determines the voltage equivalence coefficient based on the transformer's turns ratio. Let the transformer turns ratio be... (The ratio of primary voltage to secondary voltage), then the voltage equivalence factor. .

[0134] Finally, multiplying the total DC voltage by the voltage equivalence factor yields the equivalent virtual DC bus voltage on the motor side:

[0135]

[0136] The equivalent virtual DC bus voltage represents the equivalent DC bus voltage value referred from the inverter side to the motor side. In subsequent normalized modulation, this equivalent virtual DC bus voltage is used as the modulation reference, ensuring that the voltage command output by the modulation can correctly reflect the voltage amplitude required by the motor side, thereby guaranteeing the consistency of modulation parameters under different transformer turns ratios.

[0137] In some specific implementations, the controller pre-stores a mapping table between wiring groups and fixed phase shift angles. This mapping relationship is determined according to the standard definition of transformer wiring groups and can be adapted to different wiring groups such as Dyn11 and Yd11. It can also be extended to other motor drive systems containing transformers or fixed phase shift elements.

[0138] Transformer connection groups are used to indicate the connection method of the primary and secondary windings of a transformer and the phase relationship between the primary and secondary line voltages. Common connection groups include:

[0139] Yy0, Dd0, etc.: The primary and secondary line voltages are in phase and have no phase shift. ;

[0140] Dyn11, Yd11, etc.: The secondary line voltage leads the primary line voltage by 30 degrees. ;

[0141] Dyn1, Yd1, etc.: The secondary line voltage lags the primary line voltage by 30 degrees. ;

[0142] Other wiring groups: determined based on the corresponding phase difference. The value of .

[0143] The controller is based on the wiring group of the transformer actually used. Query the above mapping relationship to determine the corresponding fixed phase shift angle. :

[0144]

[0145] in, This represents the mapping function between the wiring group and the fixed phase shift angle.

[0146] It should be noted that the 30-degree figure mentioned above is only an example of phase shift for common wiring groups. For other wiring groups with different phase shifts (such as wiring groups with phase shifts of 60 degrees, 90 degrees, etc.), the figure may vary. The corresponding positive or negative angle is taken accordingly, and the protection scope of this invention is not limited to the scenario of 30-degree phase shift.

[0147] In one specific implementation, in step S103, rotational compensation is performed on the equivalent current on the motor side based on a fixed phase shift angle to obtain the compensated current in the following specific way:

[0148] First, the controller is based on a fixed phase shift angle. Determine the rotation compensation matrix The rotation compensation matrix is ​​a standard two-dimensional rotation matrix, capable of rotating vectors in... Rotation in stationary coordinate system angle.

[0149] Secondly, the controller obtains the equivalent current on the motor side. Components in stationary coordinate system , For the equivalent current on the motor side that has already undergone amplitude conversion, the Clarke transformation (3 / 2 transformation) is used to transform it from the three-phase stationary coordinate system to... Two stationary coordinate systems are obtained , Quantity.

[0150] Then, rotation compensation is performed on each component using a rotation compensation matrix:

[0151]

[0152] in, , This represents the current component in the equivalent stationary coordinate system on the motor side after compensation.

[0153] Finally, based on the compensated current components , The compensated current is synthesized. In specific implementations, the compensated current can be directly obtained as... The coordinate system components are used in subsequent vector control calculations (such as flux linkage observation, Park transformation, etc.) without needing to be recombined into three-phase currents.

[0154] For any vector in a stationary coordinate system The phase compensation formula for the wiring group is as follows:

[0155]

[0156]

[0157] The relationship between the above amplitude conversion and phase compensation can be found in [reference needed]. Figure 3 . Figure 3 In the middle, the left side represents the data sampled or calculated from the inverter side. The coordinate system electrical quantities, with the right side representing the phase shift angle after passing through the wiring group. Compensated motor side equivalent Coordinate system electrical quantities. Through this compensation, subsequent flux linkage observation, current regulation, and output reconstruction are all based on the equivalent reference system on the motor side, eliminating the impact of phase offset introduced by the transformer connection group on control accuracy.

[0158] In some implementations, the specific method for superimposing the voltage command with a fixed phase shift angle to obtain the reconstructed voltage command in the stationary coordinate system in step S105 is as follows:

[0159] First, the controller obtains the motor-side electrical angle of the asynchronous motor vector control link. The fixed phase shift angle determined by the wiring group compensation unit .

[0160] Among them, the electric angle on the motor side It serves as the basis for magnetic field orientation in the vector control link of an asynchronous motor, provided by a flux linkage observer or velocity observer. In vector control, electrical angles are used for coordinate transformation (Park transformation and inverse Park transformation), which is essential for achieving... Key parameters for shaft decoupling control. Fixed phase shift angle. This is a fixed phase offset introduced by the transformer connection group.

[0161] Secondly, the controller will adjust the electric angle on the motor side. Superimposed fixed phase shift angle The reconstruction perspective is obtained as follows: This reconfiguration angle takes into account the phase shift introduced by the transformer connection group, so that the voltage vector of the subsequent output reconfiguration can compensate for the transformer's influence in phase.

[0162] Finally, the controller reconstructs the angle. An inverse Park transformation is performed to obtain the reconstructed voltage command in the stationary coordinate system. This output reconstruction method ensures that the voltage vector actually output by the frequency converter, after passing through the transformer, is consistent with the amplitude and phase of the voltage vector required by the motor side, thereby guaranteeing the accuracy of vector control.

[0163] In one specific implementation, such as Figure 4 As shown, the transformer-crossing closed-loop vector control method of the present invention specifically includes the following steps:

[0164] S1, the controller reads the transformer configuration parameters, including: enable status, transformer turns ratio parameters, connection group parameters, and sampling position parameters, etc.

[0165] S2, obtain the equivalent sampling current on the motor side. If the current sampling point is located on the output side of the high-voltage frequency converter and the primary side of the transformer, the controller converts the primary side sampling current into the equivalent current on the secondary side of the transformer and the input side of the motor according to the transformer current equivalence coefficient and the phase shift angle of the connection group; if the current sampling point is located on the secondary side of the transformer and the input side of the motor, the secondary side sampling current is directly used as the equivalent current on the motor side.

[0166] S3, construct an equivalent virtual DC bus on the motor side. The controller obtains the equivalent modulation reference on the motor side based on the DC voltage of the high-voltage frequency converter power unit, the number of series unit stages, and the transformer voltage equivalence coefficient.

[0167] S4 determines the fixed phase shift angle according to the transformer connection group and performs rotational compensation on the voltage, current or flux linkage related electrical quantities in the stationary coordinate system.

[0168] S5 inputs the compensated electrical quantities into the asynchronous motor vector control link, so that flux observation, speed observation, current regulation and closed-loop operation are all based on the same equivalent reference frame on the motor side.

[0169] S6, will The shaft voltage command is reconstructed by outputting the electrical angle after superimposing the phase shift angle of the transformer.

[0170] S7 performs normalized modulation based on the equivalent virtual DC bus on the motor side to generate the output modulation amount of the high-voltage frequency converter.

[0171] This invention also provides an asynchronous motor testing system; please refer to [link / reference]. Figure 5 This includes frequency converters, transformers, current sampling devices, and controllers.

[0172] The primary side of the frequency converter is connected to the power grid or test power supply to convert AC power from the power grid into AC power output with adjustable frequency and voltage.

[0173] Preferably, the frequency converter is a high-voltage frequency converter (such as a 10kV-level unit series multilevel high-voltage frequency converter), which has a higher output voltage and a larger capacity margin.

[0174] The primary side of the transformer is connected to the secondary side of the frequency converter, and the secondary side of the transformer is connected to the asynchronous motor under test. The transformer is used to convert the voltage output by the frequency converter to the voltage level required by the motor under test.

[0175] Preferably, the transformer is a step-down transformer, which steps down the high voltage output (e.g., 10kV) of the high voltage frequency converter to a low voltage or medium voltage (e.g., 380V, 690V, 1140V, 3kV, 3.3kV, etc.) to adapt to the asynchronous motor under test with different voltage levels.

[0176] The current sampling device is located on the primary or secondary side of the transformer and is used to sample the current. The current sampling device can be a Hall effect current sensor, a current transformer, or other types of current sensing elements. The sampled current signal is transmitted to the controller.

[0177] The controller is connected to the current sampling device, the frequency converter, and the transformer to execute the cross-transformer vector control method for an asynchronous motor test platform as described in any of the above embodiments. Specifically, the controller acquires the current sampling signal, transformer turns ratio parameters, transformer connection group parameters, and sampling position parameters, executes the cross-transformer vector control algorithm, and generates control signals to control the output of the frequency converter.

[0178] This test system incorporates the transformer turns ratio, connection group phase shift, and sampling position into the vector control link through the transformer equivalent control layer in the controller. This ensures that sampling, coordinate transformation, flux linkage observation, current regulation, and modulation output all operate under a unified motor-side equivalent reference system, effectively solving the impact of amplitude changes and phase shifts introduced by the transformer on vector control.

[0179] In some implementations, the frequency converter is a high-voltage frequency converter, and the transformer is a step-down transformer. The output of the high-voltage frequency converter is adapted to asynchronous motors of different voltage levels via the step-down transformer, thereby enabling the same test platform to drive motors of different voltage levels for testing.

[0180] Please see Figure 6 , Figure 6 A schematic diagram of the module structure of a cross-transformer vector control system according to an embodiment of the present invention is shown. Figure 6 As shown, the control system includes:

[0181] The parameter configuration unit is used to obtain the configuration parameters of the frequency converter, the configuration parameters of the transformer, and the current sampling location. The configuration parameters of the transformer include the wiring group.

[0182] The virtual bus calculation unit is used to construct the equivalent virtual DC bus voltage on the motor side based on the configuration parameters of the frequency converter and transformer.

[0183] The electrical quantity equivalent unit is used to convert the original sampled current into an equivalent current on the motor side based on the sampling location of the original sampled current.

[0184] The connection group compensation unit is used to determine the fixed phase shift angle according to the connection group of the transformer, and to perform rotational compensation on the equivalent current on the motor side based on the fixed phase shift angle to obtain the compensated current.

[0185] The vector control calculation unit takes the compensated current as input and performs flux observation, speed observation and current regulation based on the equivalent reference frame on the motor side to obtain voltage commands.

[0186] The output reconstruction unit is used to superimpose the voltage command with a fixed phase shift angle to obtain the reconstructed voltage command in the stationary coordinate system;

[0187] The modulation output unit is used to normalize and modulate the reconstructed voltage command based on the equivalent virtual DC bus voltage to obtain the modulation amount used to control the inverter output, and then output it to the inverter.

[0188] In some implementations, the electrical quantity equivalent unit is specifically used for:

[0189] If the sampling location is the primary side of the transformer, the original sampling current is converted into the equivalent current on the secondary side according to the transformer's turns ratio parameters, and used as the equivalent current on the motor side.

[0190] If the sampling location is the secondary side of the transformer, the original sampled current is directly used as the equivalent current on the motor side.

[0191] In some implementations, the virtual bus calculation unit includes:

[0192] The first calculation subunit is used to calculate the total DC voltage of the inverter based on the number of series power unit stages per phase of the inverter and the DC voltage of a single power unit.

[0193] The second calculation subunit is used to multiply the total DC voltage by the voltage equivalence coefficient of the transformer to obtain the equivalent virtual DC bus voltage on the motor side.

[0194] In some implementations, the wiring group compensation unit includes:

[0195] The mapping subunit is used to query the fixed phase shift angle corresponding to the transformer's connection group based on the preset mapping relationship between the connection group and the fixed phase shift angle.

[0196] The first compensation subunit is used to determine the rotating compensation matrix based on the fixed phase shift angle of the transformer;

[0197] The second compensation subunit is used to obtain the components of the equivalent current on the motor side in the stationary coordinate system, and to perform rotation compensation on each component using a rotation compensation matrix to obtain the compensated current components.

[0198] In some implementations, the output reconstruction unit includes:

[0199] The data acquisition subunit is used to acquire the motor-side electrical angle of the asynchronous motor vector control link. The fixed phase shift angle determined by the wiring group compensation unit ;

[0200] Angle reconstruction subunit is used to superimpose the fixed phase shift angle onto the electrical angle on the motor side. To obtain the reconstruction angle ;

[0201] The Park transformation unit is used to perform an inverse Park transformation on the reconstruction angle to obtain the reconstruction voltage command in the stationary coordinate system.

[0202] Embodiments of the present invention also provide a controller, including one or more processors and a storage device. The storage device is used to store one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors cause the one or more processors to implement the cross-transformer vector control method for an asynchronous motor test platform as described in any of the above embodiments.

[0203] The controller can exist independently of the frequency converter, connected to it as a separate hardware device; alternatively, it can be integrated within the frequency converter as part of its control system. By receiving current sampling signals and transformer configuration parameters (turn ratio, wiring group, sampling position, etc.), the controller executes the aforementioned cross-transformer vector control method, generating control signals that are output to the frequency converter to achieve vector control of the motor.

[0204] Specifically, the controller includes a transformer equivalent control layer and an asynchronous motor vector control link. See also Figure 7 As shown, it illustrates a schematic diagram of the integration of the transformer equivalent control layer and the vector control link.

[0205] Among them, the transformer equivalent control layer executes:

[0206] The steps to construct the equivalent virtual DC bus voltage on the motor side based on the configuration parameters of the frequency converter and transformer;

[0207] The step of converting the original sampled current into the equivalent current on the motor side based on the location of the current sampling device;

[0208] The steps include determining the fixed phase shift angle based on the transformer's connection group, and performing rotational compensation on the equivalent current on the motor side based on the fixed phase shift angle to obtain the compensated current; and...

[0209] The step of inputting the compensated current into the vector control link of the asynchronous motor;

[0210] Vector control link execution:

[0211] The steps involve using the compensated current as feedback input, performing flux linkage observation, speed observation, and current regulation based on the equivalent reference frame on the motor side, and obtaining the voltage command.

[0212] The steps for superimposing voltage commands with a fixed phase shift angle to obtain reconstructed voltage commands in the stationary coordinate system; and...

[0213] The steps are as follows: normalizing and modulating the reconstructed voltage command based on the equivalent virtual DC bus voltage to obtain the modulation amount used to control the inverter output, and then outputting it to the inverter.

[0214] Embodiments of the present invention also provide an electronic device comprising a processor and a memory, wherein the number of processors may be one or more. The memory, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules. The processor executes various functional applications and data processing of the electronic device by running the software programs, instructions, and modules stored in the memory, thereby implementing the cross-transformer vector control method for an asynchronous motor test platform according to any of the above embodiments of the present invention.

[0215] The memory may primarily comprise a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a given function; the data storage area may store data created based on terminal usage. Furthermore, the memory may include high-speed random access memory (RAM) and non-volatile memory, such as at least one disk storage device, flash memory, or other non-volatile solid-state storage device. In some instances, the memory may further include memory remotely located relative to the processor, which can be connected to the electronic device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks (LANs), mobile communication networks, and combinations thereof.

[0216] Embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the cross-transformer vector control method for an asynchronous motor test platform according to any embodiment of the present invention.

[0217] The computer storage medium of this invention can be any combination of one or more computer-readable media. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this invention, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0218] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0219] Embodiments of the present invention also provide a computer program product that, when run on a computer, causes the computer to execute the cross-transformer vector control method for an asynchronous motor test platform according to any of the above embodiments of the present invention.

[0220] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A cross-transformer vector control method for an asynchronous motor test platform, characterized in that, The asynchronous motor test platform includes a frequency converter, a transformer, and an asynchronous motor under test connected in sequence; the method includes: Based on the configuration parameters of the frequency converter and transformer, an equivalent virtual DC bus voltage is constructed on the motor side; Based on the sampling location of the original sampling current, the original sampling current is converted into an equivalent current on the motor side, wherein the sampling location is the primary side or the secondary side of the transformer; The fixed phase shift angle is determined according to the connection group of the transformer, and the equivalent current on the motor side is rotated and compensated based on the fixed phase shift angle to obtain the compensated current. The compensated current is input into the asynchronous motor vector control link to perform flux linkage observation, speed observation and current regulation based on the equivalent reference frame on the motor side, and obtain voltage commands. The voltage command is superimposed with the fixed phase shift angle to obtain the reconstructed voltage command in the stationary coordinate system; The reconstructed voltage command is normalized and modulated based on the equivalent virtual DC bus voltage to obtain a modulation amount for controlling the output of the frequency converter, and then output to the frequency converter.

2. The cross-transformer vector control method for an asynchronous motor test platform according to claim 1, characterized in that, Based on the sampling location of the original sampled current, the original sampled current is converted into an equivalent current on the motor side, including: If the sampling location is the primary side of the transformer, the original sampling current is converted into the equivalent current on the secondary side according to the transformer's turns ratio parameters, and used as the equivalent current on the motor side. If the sampling location is the secondary side of the transformer, the original sampled current is directly used as the equivalent current on the motor side.

3. The cross-transformer vector control method for an asynchronous motor test platform according to claim 1, characterized in that, Based on the configuration parameters of the frequency converter and transformer, an equivalent virtual DC bus voltage is constructed on the motor side, including: Calculate the total DC voltage of the frequency converter based on the number of series power units in each phase of the frequency converter and the DC voltage of a single power unit; Multiplying the total DC voltage by the voltage equivalence factor of the transformer yields the equivalent virtual DC bus voltage on the motor side.

4. The cross-transformer vector control method for an asynchronous motor test platform according to claim 1, characterized in that, Determining the fixed phase shift angle based on the transformer's connection group includes: querying the fixed phase shift angle corresponding to the transformer's connection group based on a preset mapping relationship between connection groups and fixed phase shift angles; The mapping relationship between the transformer's connection group and the fixed phase shift angle is as follows: ； in, Indicates the connection group of the step-down transformer. A fixed phase shift angle; This represents the mapping function; for non-phase shift connection groups, Pick For those with The wiring group of phase shift, According to the corresponding connection method degree or Spend.

5. The cross-transformer vector control method for an asynchronous motor test platform according to claim 1 or 4, characterized in that, Based on the fixed phase shift angle, rotational compensation is performed on the equivalent current on the motor side to obtain the compensated current, including: The rotation compensation matrix is ​​determined based on the fixed phase shift angle; Obtain the components of the equivalent current on the motor side in the stationary coordinate system, and use the rotation compensation matrix to perform rotation compensation on each component to obtain the compensated current components. The compensated current is obtained based on the compensated current components.

6. The cross-transformer vector control method for an asynchronous motor test platform according to claim 5, characterized in that, The rotation compensation matrix is ​​expressed as: ； in, This indicates the fixed phase shift angle determined by the wiring group.

7. The cross-transformer vector control method for an asynchronous motor test platform according to claim 1, characterized in that, The voltage command is superimposed with the fixed phase shift angle to obtain the reconstructed voltage command in the stationary coordinate system, including: Obtain the motor-side electrical angle of the asynchronous motor vector control link. The fixed phase shift angle ; The electric angle of the motor side Superimposed fixed phase shift angle To obtain the reconstruction angle ; Regarding the reconstructed angle to counter The transformation yields the reconstructed voltage command in the stationary coordinate system.

8. A controller, characterized in that, include: One or more processors; Storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the cross-transformer vector control method for an asynchronous motor test platform as described in any one of claims 1-7.

9. An asynchronous motor testing system, characterized in that, include: The frequency converter, wherein the primary side of the frequency converter is connected to the power grid or test power supply; A transformer, the primary side of which is connected to the secondary side of the frequency converter, and the secondary side of which is connected to the asynchronous motor under test; A current sampling device, located on the primary or secondary side of the transformer, is used to sample the current; The controller, connected to the current sampling device, frequency converter, and transformer, is used to execute the cross-transformer vector control method for an asynchronous motor test platform as described in any one of claims 1-7.

10. The asynchronous motor testing system according to claim 9, characterized in that, The frequency converter is a high-voltage frequency converter, and the transformer is a low-voltage transformer.

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