A PMSM harmonic current test system of a hydrogen fuel cell vehicle

Abstract

The present application relates to the technical field of permanent magnet synchronous motor, and discloses a PMSM harmonic current test system of hydrogen fuel cell vehicle, which comprises a first monitoring module, a second monitoring module, a motor driving module, a motor load module and an electric energy quality analysis module.The first monitoring module determines the target rotating speed through the rotating speed adjusting instruction, and adjusts the target rotating speed of the motor driving module for multiple times within the given test time period, so as to simulate the frequent acceleration, deceleration, idling and parking and other operating states of the hydrogen fuel cell vehicle, form the time-varying characteristics of the PMSM harmonic current, and facilitate the detection and analysis.Combined with the second monitoring module, the target torque of the motor load module is determined through the torque adjusting instruction, and various working condition test function test requirements are realized through different rotating speeds and torques, so that the test system can maintain extremely high stability within the whole rotating speed or at zero rotating speed and torque range, and can accurately reflect the characteristics of the harmonic current of the actual PMSM in the operating process of the hydrogen fuel cell vehicle.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet synchronous motors, and in particular to a PMSM harmonic current testing system for hydrogen fuel cell vehicles. Background Technology

[0002] The power system of a hydrogen fuel cell vehicle (HFCV) is the core component. The permanent magnet synchronous motor (PMSM) provides power to the hydrogen fuel cell vehicle, and the motor controller MCU (SVPWM and inverter) is the core component that drives and controls the PMSM, directly determining the overall performance of the HFCV.

[0003] PMSMs suffer from cogging effects and air gap magnetic field distortion caused by rotor pole structure. Inverters also exhibit nonlinear characteristics such as dead time and tube voltage drop, resulting in harmonic currents during PMSM operation. This causes additional losses, torque fluctuations, and reduced HFCV operating performance. Furthermore, the frequent acceleration, deceleration, idling, and stopping during HFCV operation lead to time-varying harmonic currents in the PMSM (time-varying harmonic currents), the amplitude and phase of which are determined by PMSM speed and parameters, inverter parameters, and other factors.

[0004] Currently, research on the current characteristics and suppression strategies of PMSM harmonic current in hydrogen fuel cell vehicles is usually verified through simulation. However, there is still a certain gap between simulation and actual use, making it difficult to accurately test and verify the current characteristics of PMSM harmonic current in hydrogen fuel cell vehicles. Summary of the Invention

[0005] The purpose of this invention is to provide a PMSM harmonic current testing system for hydrogen fuel cell vehicles, in order to solve one or more technical problems existing in the prior art, or at least provide a beneficial option or create conditions.

[0006] To address the aforementioned problems, in some embodiments of the present invention, a PMSM harmonic current testing system for hydrogen fuel cell vehicles is provided, comprising:

[0007] The first monitoring module is used to respond to the speed adjustment command, determine the target speed according to the speed adjustment command and the set speed adjustment step size, and adjust the target speed according to the set time step size within a given test time period.

[0008] The motor drive module is communicatively connected to the first monitoring module and is used to run at the target speed to simulate the operating state of a hydrogen fuel cell vehicle.

[0009] The second monitoring module is used to respond to torque adjustment commands and determine the target torque based on the torque adjustment commands and the set torque adjustment step size.

[0010] The motor load module is coaxially connected to the motor drive module and is communicatively connected to the second monitoring module. The motor load module is used to run the target torque to simulate the operating load of a hydrogen fuel cell vehicle.

[0011] A power quality analysis module is connected to the motor drive module. The power quality analysis module is used to detect the harmonic current generated by the motor drive module and analyze the characteristics of the harmonic current.

[0012] Furthermore, the motor drive module includes:

[0013] Drive motor;

[0014] The first motor controller is connected to the drive motor and communicates with the first monitoring module. The first motor controller is used to drive the drive motor to run at the target speed.

[0015] Furthermore, the motor load module includes:

[0016] A load motor, wherein the load motor and the drive motor are coaxially connected in the same direction;

[0017] The second motor controller is connected to the drive motor and communicates with the second monitoring module. The second motor controller is used to drive the load motor to run according to the target torque.

[0018] Furthermore, the first motor controller is equipped with a speed closed-loop control module; the speed closed-loop control module is used to obtain the current speed of the drive motor and perform closed-loop regulation on the current speed so that the current speed tracks the target speed.

[0019] Furthermore, the second motor controller is equipped with a torque closed-loop control module; the torque closed-loop control module is used to obtain the current torque of the load motor and perform closed-loop regulation on the current torque so that the current torque tracks the target torque.

[0020] Furthermore, the PMSM harmonic current testing system also includes:

[0021] The first DC bus is connected to the motor drive module;

[0022] The second DC bus is connected to the motor load module;

[0023] A high-voltage current limiting module, the output terminal of which is connected to the first DC bus and the second DC bus respectively, is used to limit the inrush current generated when the external high-voltage power supply terminal is input;

[0024] A bidirectional DC power supply module, wherein the input terminal of the bidirectional DC power supply module is connected to an external high-voltage power supply terminal, and the output terminal of the bidirectional DC power supply module is connected to the first DC bus and the second DC bus respectively through a high-voltage current limiting module;

[0025] The bidirectional DC power supply module is used to output a first DC power supply to the motor drive module through the high-voltage current limiting module and the first DC bus, and to output a second DC power supply to the motor load module through the high-voltage current limiting module and the second DC bus.

[0026] Furthermore, the PMSM harmonic current testing system also includes: a constant temperature cooling module;

[0027] The outlet of the constant temperature cooling module is connected to the inlet of the first motor controller, and the inlet of the constant temperature cooling module is connected to the outlet of the load motor; wherein, the outlet of the first motor controller is connected to the inlet of the second motor controller, the outlet of the second motor controller is connected to the inlet of the drive motor, and the outlet of the drive motor is connected to the inlet of the load motor.

[0028] The constant temperature cooling module is used to circulate and cool the first motor controller, the second motor controller, the drive motor and the load motor through cooling water, and to regulate the temperature of the cooling water.

[0029] Furthermore, the PMSM harmonic current testing system also includes:

[0030] Spline shaft;

[0031] The first coupling has its two ends coaxially connected to a splined shaft and a drive motor, respectively;

[0032] The second coupling has its two ends coaxially connected to the splined shaft and the load motor, respectively.

[0033] Furthermore, the constant temperature cooling module includes:

[0034] A water tank, wherein the outlet of the water tank is connected to the inlet of the first motor controller, and the inlet of the water tank is connected to the outlet of the load motor. Both the outlet and inlet of the water tank are equipped with temperature detectors. The water tank is used to store the cooling water.

[0035] A cooling fan is connected to the temperature detector and is used to regulate the temperature of the cooling water.

[0036] A water pump, the water pump being used to pump the cooling water to the inlet of the first motor controller.

[0037] Furthermore, the PMSM harmonic current testing system also includes: a first communication module; the input terminal of the first communication module is connected to the two communication ports of the bidirectional DC power supply, and the output terminal of the first communication module is connected to the first monitoring module.

[0038] The beneficial effects of this invention are as follows: The first monitoring module determines the target speed through speed adjustment commands and adjusts the target speed of the motor drive module multiple times within a given test period to simulate the frequent acceleration, deceleration, idling, and parking of a hydrogen fuel cell vehicle, thereby forming the time-varying characteristics of the PMSM harmonic current for detection and analysis. Combined with the second monitoring module determining the target torque of the motor load module through torque adjustment commands, various operating conditions and test requirements are met through different speeds and torques. This allows the test system to maintain extremely high stability throughout the entire speed range or at zero speed and within the torque range, while accurately reflecting the characteristics of the harmonic current of the actual PMSM during the operation of a hydrogen fuel cell vehicle. This reduces the gap in the actual operation of a hydrogen fuel cell vehicle using the PMSM and facilitates the accurate testing and verification of the current characteristics of the PMSM harmonic current in a hydrogen fuel cell vehicle. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure of a PMSM harmonic current testing system for a hydrogen fuel cell vehicle, as shown in an embodiment of the present invention. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the present invention will be further described below in conjunction with the embodiments and accompanying drawings.

[0041] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0042] Reference Figure 1 In some embodiments of the present invention, a PMSM harmonic current testing system for a hydrogen fuel cell vehicle includes: a first monitoring module, a second monitoring module, a motor drive module, a motor load module, and a power quality analysis module.

[0043] The first monitoring module is connected to the motor drive module, the second monitoring module is connected to the motor load module, and the power quality analysis module is connected to the motor drive module.

[0044] The first monitoring module responds to the speed adjustment command, determines the target speed for the motor drive module based on the command and the set speed adjustment step size, and sends the target speed to the motor drive module. The first monitoring module also adjusts the target speed multiple times within a given test period, using a set time step.

[0045] The motor drive module operates according to the target speed issued by the first monitoring module to simulate the frequent acceleration, deceleration, idling and stopping of a hydrogen fuel cell vehicle.

[0046] In one embodiment, the first monitoring module responds to the speed adjustment command, determines the target speed, sends the target speed to the motor drive module, and then adjusts the target speed again with a set time step, and responds to the speed adjustment command again, thereby simulating the frequent acceleration, deceleration, idling and stopping, as well as different operating speeds during the operation of a hydrogen fuel cell vehicle, resulting in time-varying PMSM harmonic current.

[0047] The second monitoring module responds to the torque adjustment command, determines the target torque for the motor load module based on the torque adjustment command and the set torque adjustment step size, and sends the target torque to the motor load module.

[0048] The motor load module operates according to the target torque issued by the second monitoring module to simulate the operating load of a hydrogen fuel cell vehicle.

[0049] The initial speed value and the set speed adjustment step size of the motor drive module can be set by the first monitoring module, and the initial torque value and the set torque adjustment step size of the motor load module can be set by the second monitoring module.

[0050] The power quality analysis module can detect voltage and current signals and obtain power parameters such as harmonic current, active power, reactive power, and power factor through analysis and processing.

[0051] In this embodiment, the power quality analysis module can detect harmonic currents in the motor drive module and obtain the characteristics of PMSM harmonic currents in the hydrogen fuel cell vehicle through analysis and processing.

[0052] The above embodiments utilize a first monitoring module to regulate the motor drive module, simulating frequent acceleration, deceleration, idling, and stopping during the operation of a hydrogen fuel cell vehicle. This generates time-varying characteristics of the PMSM harmonic current, facilitating subsequent detection and analysis. Combined with the second monitoring module's regulation of the motor load module, the operating load of the hydrogen fuel cell vehicle is simulated. Various operating conditions and test requirements are met through different speeds and torques. This allows the test system to maintain extremely high stability throughout the entire speed range or at zero speed and within the torque range, accurately reflecting the harmonic current characteristics of the actual PMSM during hydrogen fuel cell vehicle operation. This reduces the discrepancies in actual PMSM usage during hydrogen fuel cell vehicle operation and facilitates precise testing and verification of the PMSM harmonic current characteristics in hydrogen fuel cell vehicles.

[0053] Reference Figure 1 In some embodiments of the present invention, the motor drive module includes: a drive motor and a first motor controller.

[0054] The first motor controller is connected to the drive motor, the first motor controller is connected to the power quality analysis module, and the first motor controller is also connected to the first monitoring module. The first motor controller can control the drive motor to run at the target speed.

[0055] The first motor controller communicates with the first monitoring module via the CAN communication protocol. The drive motor is a TZ185XSTY3202 permanent magnet synchronous motor, and the first motor controller is a KTZ54X35STY60 motor controller.

[0056] In one embodiment, the motor load module includes: a load motor and a second motor controller.

[0057] The load motor and the drive motor are positioned facing each other and are coaxially connected, meaning that the load motor and the drive motor are coaxially connected back to back.

[0058] The second motor controller is connected to the load motor and also communicates with the second monitoring module. The second motor controller can control the load motor to run at the target torque.

[0059] The second motor controller communicates with the second monitoring module via the CAN communication protocol. The load motor is a TZ185XSTY3202 permanent magnet synchronous motor, and the second motor controller is a KTZ54X35STY60 motor controller.

[0060] Reference Figure 1 In some embodiments of the present invention, the PMSM harmonic current testing system further includes: a splined shaft, a first coupling, and a second coupling.

[0061] One end of the splined shaft is coaxially connected to one end of the first coupling, and the other end of the splined shaft is coaxially connected to one end of the second coupling. The other end of the first coupling is coaxially connected to the drive motor, and the other end of the second coupling is coaxially connected to the load motor.

[0062] Reference Figure 1 In some embodiments of the present invention, the first motor controller is provided with a speed closed-loop control module. The drive motor operates in speed closed-loop mode. When power is supplied to the drive motor, the output frequency of the first motor controller is equal to the synchronous speed frequency of the drive motor, and the drive motor is in motoring mode.

[0063] Considering the interference factors in the operation of the PMSM drive motor, such as cogging effect, air gap magnetic field distortion caused by rotor pole structure, dead time of inverter, and current sampling error, the speed closed-loop control module obtains the current speed of the drive motor. Based on the interference factors and the mechanical dynamic equation of the drive motor, it derives the dynamic equation of speed trajectory tracking error. Using the dynamic equation of speed trajectory tracking error and adaptive control algorithm, it regulates the first motor controller to achieve closed-loop control of the current speed, enabling the current speed to track the target speed.

[0064] In one embodiment, the closed-loop speed control process using a speed closed-loop control module is as follows:

[0065] The mechanical dynamic equation of the drive motor is:

[0066]

[0067] Where, ω m Where J is the mechanical rotational speed, and T is the moment of inertia. L Where B is the load torque, and T is the coefficient of friction. e For electromagnetic torque, its expression is:

[0068]

[0069] Where, p n Let ψ be the extreme logarithm. f For permanent magnet flux linkage, I s L is the stator current, β is the angle between the stator flux linkage and the permanent magnet flux linkage. d and L q These are the d-axis inductance and q-axis inductance of the motor, respectively.

[0070] Integrating the mechanical dynamic equations and expressions, and updating the mechanical dynamic equations, we obtain:

[0071]

[0072]

[0073] Due to interference factors such as cogging effect in the motor drive module, air gap magnetic field distortion caused by rotor pole structure, flux linkage harmonics, dead time in the inverter, and current sampling error, the mechanical dynamic equations are updated again based on these interference factors, resulting in:

[0074]

[0075] Among them, T h =f(T) cog ,ψ h ,u h i e ), T cog For cogging torque, ψ h For magnetic flux harmonics, u h For voltage harmonics, i e This represents the current sampling error.

[0076] Let f total Given the total disturbance of the motor drive module, the mechanical dynamic equations are updated for the third time, yielding...

[0077]

[0078] Among them, f total =T d +T h +ΔbI s Δb=b-b0, and the speed trajectory tracking error is defined as e. m =ω m,ref -ω m According to the third updated mechanical dynamic equation, the speed trajectory tracking error e m The dynamic equation can be derived as follows:

[0079]

[0080] Among them, f e The total disturbance in the error dynamic equation includes not only the original total disturbance from the speed closed loop but also the differential value of the reference speed. Furthermore, the total disturbance f varies depending on the different effects of various disturbances. e Disturbances can be divided into aperiodic disturbances and periodic disturbances, as follows:

[0081] f e =f ap +f p

[0082] Among them, f ap =-T d -ΔbI s +dω m,ref / dt,f p=-T h f ap This refers to aperiodic disturbances, primarily disturbances in the form of constants within the speed loop, f p This refers to periodic disturbances, primarily sinusoidal disturbances within the speed closed loop.

[0083] For the dynamic equation of the speed trajectory tracking error, the speed trajectory tracking error e m The reference value can be considered zero, so the control objective is: under the influence of multi-source disturbances (periodic and aperiodic disturbances), to adjust the stator current I... s This reduces the speed trajectory tracking error e m It is zero.

[0084] In this embodiment, the first motor controller is regulated using a single-degree-of-freedom adaptive control algorithm (ADRC) and the dynamic equation of the speed trajectory tracking error to achieve closed-loop control of the current speed, thereby achieving the speed control objective: the current speed can accurately track the target speed.

[0085] The total disturbance f in the dynamic equation of the speed trajectory tracking error e The state is expanded to a new state variable, and the expanded state equation is:

[0086]

[0087] Among them, z e It is the total disturbance f e The differential value of is bounded.

[0088] Single-degree-of-freedom adaptive control algorithms include an extended state observer (ESO) and a control law. Based on the extended state equations, the extended state observer can be designed as follows:

[0089]

[0090] Here, the state variables marked with "^" are the estimated values ​​of their corresponding variables, and h1 and h2 are the gains of the Extended State Observer (ESO). The gain of the Extended State Observer can then be designed as:

[0091] h1=2ω o ,

[0092] Where, ω o To extend the bandwidth of the state observer, ω o The magnitude of the value directly determines how quickly the extended state observer can estimate the disturbance response.

[0093] The control law can be designed as follows:

[0094]

[0095] Among them, K e For the bandwidth of the control law, K e =ω c ω c The magnitude of the bandwidth directly determines the speed of the dynamic response at rotational speed. The bandwidth mentioned above can be a constant.

[0096] Substituting the control law into the speed trajectory tracking error e m From the dynamic equation, the error closed-loop transfer equation can be derived:

[0097]

[0098] According to the error closed-loop transfer equation, when the total disturbance f is accurately estimated using the extended state observer... e Speed ​​trajectory tracking error e m If its first derivative is zero, then the speed control target of accurately tracking the reference speed can be achieved, that is, the speed control target of tracking the target speed can be achieved.

[0099] Reference Figure 1 In some embodiments of the present invention, the second motor controller is equipped with a torque closed-loop control module. This module acquires the current torque of the load motor, which operates in a torque closed-loop manner. The second motor controller controls the electromagnetic torque variation of the load motor, enabling its current torque to track the target torque, thereby simulating the load magnitude of a hydrogen fuel cell electric vehicle. Specifically, when supplying power to the load motor, the output frequency of the second motor controller is lower than the synchronous speed frequency of the driving motor, indicating that the load motor is in a power generation state, and the second motor controller feeds energy back to the power source.

[0100] In one embodiment, when the target torque of the load motor remains constant, and the target speed of the driven motor is adjusted by the first monitoring module, if the target speed of the driven motor changes from n1 to n2 during constant torque acceleration, the first motor controller receives a positive torque current output increment through the speed closed-loop control module, replacing the original near-zero increment. At this time, the electromagnetic torque of the driven motor increases, and the driven motor accelerates. To maintain the current torque of the load motor constant, ensuring that the current torque still tracks the target torque, the speed of the load motor increases. When the driven motor reaches a new speed equilibrium, the frequency difference between the two PMSM motors remains constant, and the driven motor and load motor reach a new torque equilibrium, thus completing the constant load acceleration process. The deceleration process is similar to the acceleration process and will not be described in detail in this embodiment.

[0101] As can be seen from the above embodiments, this application takes into account the interference factors such as the cogging effect and air gap magnetic field distortion caused by the rotor magnetic pole structure during the operation of the PMSM motor, the dead time of the inverter, and the current sampling error in the speed closed-loop control, so as to improve the accuracy of the motor speed closed-loop control, enable the driven motor to run at the target speed as much as possible, and enable the test system to maintain extremely high stability throughout the entire speed (even at zero speed) and torque range, thereby improving the accuracy and authenticity of the test system.

[0102] Reference Figure 1 In some embodiments of the present invention, the PMSM harmonic current testing system further includes: a first DC bus, a second DC bus, a high-voltage current limiting module, a bidirectional DC power supply module, and a constant temperature cooling module.

[0103] The input terminal of the bidirectional DC power supply module is connected to the external high-voltage power supply terminal, and the output terminal of the bidirectional DC power supply module is connected to the input terminal of the high-voltage current limiting module. The output terminal of the high-voltage current limiting module is connected to the first DC bus and the second DC bus respectively. In other words, the bidirectional DC power supply module can be connected to the first DC bus and the second DC bus respectively through the high-voltage current limiting module.

[0104] The first DC bus is connected to the first motor controller in the motor drive module, and the second DC bus is connected to the second motor controller in the motor load module.

[0105] When the bidirectional DC power supply module is powered by the external high-voltage power supply terminal, the high-voltage current limiting module can limit the high-voltage inrush current and prevent the high-voltage inrush current from impacting the motor drive module and motor load module through the two DC buses, thereby causing damage to the first motor controller and the second motor controller, and improving the stability of the test system.

[0106] Through the high-voltage current limiting module and the first DC bus, the bidirectional DC power supply module supplies first DC power to the first motor controller, and through the high-voltage current limiting module and the second DC bus, the bidirectional DC power supply module supplies second DC power to the second motor controller. In other words, through the high-voltage current limiting module, the first DC bus, and the second DC bus, the bidirectional DC power supply module can correspondingly supply DC power to the motor load module and the motor drive module.

[0107] By setting up a bidirectional DC power supply module, the bus voltage of the test system can be varied over a wider range, which is closer to the power system of a real vehicle. This facilitates continuous voltage adjustment, provides better dynamic characteristics, and prevents motor vibration or test errors caused by poor dynamic characteristics of DC output.

[0108] The constant temperature cooling module can circulate cooling water to the first motor controller, the second motor controller, the drive motor, and the load motor, and adjust the water temperature to achieve constant temperature control.

[0109] The constant temperature cooling module includes: a water tank, a water pump, and a cooling fan.

[0110] The water inlet of the water tank is connected to the water inlet of the first motor controller. The water outlet of the first motor controller is connected to the water inlet of the second motor controller, the water outlet of the second motor controller is connected to the water inlet of the drive motor, the water outlet of the drive motor is connected to the water inlet of the load motor, and the water outlet of the load motor is connected to the water inlet of the water tank.

[0111] The water tank stores cooling water. Temperature sensors are installed at both the inlet and outlet of the tank to detect the inlet and outlet water temperatures. A cooling fan is connected to the temperature sensors and adjusts the cooling water temperature based on the inlet and outlet temperatures, thus achieving constant temperature control. A water pump pumps the cooling water from the tank to the inlet of the first motor controller to drive the circulating flow of the cooling water.

[0112] By setting up a constant temperature cooling module with circulating cooling water, over-temperature protection is provided for the motor and motor controller.

[0113] Reference Figure 1 In some embodiments of the present invention, the PMSM harmonic current testing system further includes: a hub, a first communication module, and a second communication module.

[0114] The input terminal of the first communication module is connected to the two communication ports of the bidirectional DC power supply module, and the output terminal of the first communication module is connected to the first USB port of the first monitoring module. Monitoring of the bidirectional DC power supply module is achieved through the first communication module.

[0115] One end of the hub is connected to the constant temperature cooling module, the external high-voltage power supply, and the high-voltage current limiting module, respectively. The other end of the hub is connected to the input of the second communication module, and the output of the second communication module is connected to the second USB port of the first monitoring module. The second communication module enables monitoring of the constant temperature cooling module, the external high-voltage power supply, and the high-voltage current limiting module.

[0116] The first monitoring module has a drive motor monitoring interface and a test interface, which can display the communication status of the above-mentioned devices. The second monitoring module has a load monitoring interface.

[0117] Through the above embodiments, the present invention transmits the operating status of the bidirectional DC power supply module, the constant temperature cooling module, the external high voltage power supply terminal, and the high voltage current limiting module to the first monitoring module via the first communication module and the second communication module, thereby realizing the monitoring of the test system.

[0118] In some embodiments of the present invention, the method for testing harmonic current using the PMSM harmonic current testing system for hydrogen fuel cell vehicles of the present invention is as follows:

[0119] After confirming that the communication status is correct, respond to the start command and the external high-voltage power supply terminal supplies power to the bidirectional DC power module;

[0120] The first monitoring module responds to the power supply command and sets the power supply parameters of the first and second DC power supplies output by the bidirectional DC power supply module according to the power supply command. The bidirectional DC power supply module outputs the first and second DC power supplies.

[0121] After confirming that the constant temperature cooling module and the high voltage current limiting module have started normally, the first monitoring module responds to the harmonic current test command.

[0122] According to the harmonic current test command, the motor drive module is set to the speed closed-loop operation mode, the motor load module is set to the torque closed-loop operation mode, and the initial speed value and speed adjustment step of the motor drive module are set, as well as the initial torque value and torque adjustment step of the motor load module.

[0123] The first monitoring module responds to the speed adjustment command, determines the target speed of the motor drive module through the speed adjustment command and the set speed adjustment step size, and adjusts the target speed according to the set time step size within a given test period. The motor drive module runs at the target speed to simulate the frequent acceleration, deceleration, idling and stopping of the hydrogen fuel cell vehicle.

[0124] The second monitoring module responds to the torque adjustment command, determines the target torque of the motor load module through the torque adjustment command and the set torque adjustment step size, and the motor load module operates at the target torque to realize the operating load of the simulated hydrogen fuel cell vehicle.

[0125] During operation, the power quality analysis module is used to detect the harmonic current generated by the motor drive module, and the characteristics of the harmonic current are analyzed to verify the harmonic current.

[0126] In one embodiment, according to the harmonic current test command, the drive motor is set to the speed closed-loop operation mode. In the speed closed-loop setting, the initial speed value is set to 150 and the step size is 5. Reversing the setting indicates deceleration. The user issues a speed adjustment command with the set time step size, increases or decreases the speed according to the set speed adjustment step size, determines the target speed, and drives the motor to run at the target speed.

[0127] The motor load module is set to the torque closed-loop operation mode. In the torque closed-loop setting, the initial torque value is set to 0 and the step size is 1. Reversing the setting indicates resistance. Each time a torque adjustment command is received, the resistance is increased or decreased according to the set torque adjustment step size to determine the target torque and drive the motor to run at the target torque.

[0128] Among these methods, the harmonic current suppression method can be downloaded to the motor drive module to enable testing and verification of the current harmonic suppression method.

[0129] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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, they should be considered to be within the scope of this specification.

[0130] In this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0131] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A PMSM harmonic current testing system for hydrogen fuel cell vehicles, characterized in that, include: The first monitoring module is used to respond to the speed adjustment command, determine the target speed according to the speed adjustment command and the set speed adjustment step size, and adjust the target speed according to the set time step size within a given test time period. The motor drive module is communicatively connected to the first monitoring module and is used to run at the target speed to simulate the operating state of a hydrogen fuel cell vehicle. The second monitoring module is used to respond to torque adjustment commands and determine the target torque based on the torque adjustment commands and the set torque adjustment step size. The motor load module is coaxially connected to the motor drive module and is communicatively connected to the second monitoring module. The motor load module is used to run the target torque to simulate the operating load of a hydrogen fuel cell vehicle. A power quality analysis module, connected to the motor drive module, is used to detect harmonic currents generated by the motor drive module and analyze the characteristics of these harmonic currents. The motor drive module includes a drive motor and a first motor controller. The first motor controller is equipped with a speed closed-loop control module. The speed closed-loop control module is used to obtain the current speed of the drive motor and perform closed-loop regulation on the current speed so that the current speed tracks the target speed. The closed-loop control process using the speed closed-loop control module includes integrating the mechanical dynamic equations and expressions of the drive motor, updating the mechanical dynamic equations, and updating the mechanical dynamic equations again based on the set disturbance factors, resulting in: in, , For cogging torque, It is a magnetic flux harmonic. Voltage harmonics For current sampling error, For mechanical rotation speed, For stator current, J For rotational inertia, Where B is the load torque and B is the coefficient of friction. For extreme logarithms, It is a permanent magnet flux chain. For stator current, β The angle between the stator flux linkage and the permanent magnet flux linkage. and Motors d Shaft inductance and q Shaft inductance, where b is the gain coefficient for the rate of change of stator current with respect to mechanical speed. This refers to the disturbance terms in the motor drive module other than cogging torque, flux harmonics, and voltage harmonics. set up For the total disturbance of the motor drive module, the mechanical dynamic equations are updated for the third time, resulting in... in, , Define the speed trajectory tracking error as , This is the nominal value of b, a constant that is set. Using the reference mechanical speed, based on the third updated mechanical dynamic equation, the speed trajectory tracking error... The dynamic equation can be derived as follows: in, The total disturbance in the error dynamic equation is... Disturbances can be divided into aperiodic disturbances and periodic disturbances, as follows: ,in, , , This is an aperiodic disturbance, a disturbance in the form of a constant within the speed loop. It is a periodic disturbance, a sinusoidal disturbance within the speed closed loop; For the dynamic equation of the speed trajectory tracking error, the speed trajectory tracking error The reference value can be considered zero, so the control objective is: under periodic and aperiodic disturbances, to adjust the stator current... This reduces the tracking error of the rotational speed trajectory. The value is zero; using a single-degree-of-freedom adaptive control algorithm and the dynamic equation of the speed trajectory tracking error, the first motor controller is regulated to achieve closed-loop control of the current speed.

2. The PMSM harmonic current testing system for hydrogen fuel cell vehicles according to claim 1, characterized in that, The first motor controller is connected to the drive motor and the power quality analysis module respectively. The first motor controller is also connected to the first monitoring module. The first motor controller is used to drive the drive motor to run at the target speed.

3. The PMSM harmonic current testing system for hydrogen fuel cell vehicles according to claim 2, characterized in that, The motor load module includes: A load motor, wherein the load motor and the drive motor are coaxially connected in the same direction; The second motor controller is connected to the load motor and communicates with the second monitoring module. The second motor controller is used to drive the load motor to run according to the target torque.

4. The PMSM harmonic current testing system for hydrogen fuel cell vehicles according to claim 3, characterized in that, The second motor controller is equipped with a torque closed-loop control module; the torque closed-loop control module is used to obtain the current torque of the load motor and perform closed-loop regulation on the current torque so that the current torque tracks the target torque.

5. The PMSM harmonic current testing system for hydrogen fuel cell vehicles according to claim 1, characterized in that, Also includes: The first DC bus is connected to the motor drive module; The second DC bus is connected to the motor load module; A high-voltage current limiting module, the output terminal of which is connected to the first DC bus and the second DC bus respectively, is used to limit the inrush current generated when the external high-voltage power supply terminal is input; A bidirectional DC power supply module, wherein the input terminal of the bidirectional DC power supply module is connected to an external high-voltage power supply terminal, and the output terminal of the bidirectional DC power supply module is connected to the first DC bus and the second DC bus respectively through a high-voltage current limiting module; The bidirectional DC power supply module is used to output a first DC power supply to the motor drive module through the high-voltage current limiting module and the first DC bus, and to output a second DC power supply to the motor load module through the high-voltage current limiting module and the second DC bus.

6. The PMSM harmonic current testing system for hydrogen fuel cell vehicles according to claim 3, characterized in that, Also includes: Constant temperature cooling module; The outlet of the constant temperature cooling module is connected to the inlet of the first motor controller, and the inlet of the constant temperature cooling module is connected to the outlet of the load motor; wherein, the outlet of the first motor controller is connected to the inlet of the second motor controller, the outlet of the second motor controller is connected to the inlet of the drive motor, and the outlet of the drive motor is connected to the inlet of the load motor. The constant temperature cooling module is used to circulate and cool the first motor controller, the second motor controller, the drive motor and the load motor through cooling water, and to regulate the temperature of the cooling water.

7. The PMSM harmonic current testing system for hydrogen fuel cell vehicles according to claim 3, characterized in that, Also includes: Spline shaft; The first coupling has its two ends coaxially connected to a splined shaft and a drive motor, respectively; The second coupling has its two ends coaxially connected to the splined shaft and the load motor, respectively.

8. The PMSM harmonic current testing system for hydrogen fuel cell vehicles according to claim 6, characterized in that, The constant temperature cooling module includes: A water tank, wherein the outlet of the water tank is connected to the inlet of the first motor controller, and the inlet of the water tank is connected to the outlet of the load motor. Both the outlet and inlet of the water tank are equipped with temperature detectors. The water tank is used to store the cooling water. A cooling fan is connected to the temperature detector and is used to regulate the temperature of the cooling water. A water pump, the water pump being used to pump the cooling water to the inlet of the first motor controller.

9. The PMSM harmonic current testing system for hydrogen fuel cell vehicles according to claim 5, characterized in that, Also includes: The first communication module has its input terminal connected to the two communication ports of the bidirectional DC power supply, and its output terminal connected to the first monitoring module.

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