Dynamic measurement system and method based on double-shaft extension permanent magnet synchronous dynamometer motor

Abstract

The invention discloses a dynamic test system and method based on a double-shaft extension permanent magnet synchronous dynamometer motor, the system comprises the double-shaft extension permanent magnet synchronous dynamometer motor, two ends of the double-shaft extension permanent magnet synchronous dynamometer motor are respectively connected with a first tested motor and a second tested motor through a coupling and a measuring device, and each motor is driven by an independent four-quadrant frequency conversion controller and is uniformly and coordinately controlled by a measurement and control unit. The system supports a double-side synchronous test mode, can perform performance test on two motors at the same time, has power expansion capability, forms a double-stator structure by connecting an auxiliary synchronous motor, realizes multiplication of test power, and can independently acquire electrical and mechanical signals, execute a synchronous control strategy and perform safety monitoring by integrating a measurement and control unit with a power analysis module. The test process is stable and reliable; the test efficiency and the equipment utilization rate are improved, the test power range is expanded, and the method is suitable for motor batch detection and high-power model machine verification.

Description

A dynamic measurement system and method based on a dual-axis extended permanent magnet synchronous dynamometer motor. Technical Field

[0001] This invention relates to the field of motor testing technology, and more specifically to a dynamic testing system and method based on a dual-shaft permanent magnet synchronous dynamometer motor. Background Technology

[0002] In the field of motor manufacturing and R&D, motor dynamic testing (dynamic performance testing) is a crucial step in verifying whether the electromagnetic design, mechanical structure, and final performance of a motor meet the requirements. Traditional dynamic testing benches typically employ a "one-to-one" paired approach, where one motor under test (test motor) and one auxiliary test motor (dynamometer) are coupled together via a coupling to form a test circuit. When the test motor operates in motoring mode, the auxiliary test motor operates in generating (feeding) mode, and vice versa. Energy is fed back through a common DC bus or a common AC bus scheme.

[0003] However, this classic approach has significant limitations: First, the test bench is single-function, meaning only one motor can be tested at a time, and the test motor cannot be used for other purposes during testing, resulting in low equipment utilization. Second, the testing capability is limited by the performance limits of the test motor. When the power, torque, or speed range of the tested motor exceeds the rated capacity of the test motor, a complete or realistic test cannot be performed, limiting the applicability of the test bench.

[0004] Therefore, there is an urgent need for a new dynamic testing technology solution that can improve testing efficiency and expand the range of testing capabilities. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a dynamic testing system and method based on a dual-axis extended permanent magnet synchronous dynamometer. Through innovative structural design, control strategy, and power expansion method, this system enables simultaneous testing of two motors or high-power motors with testing power exceeding the capacity of a single dynamometer, significantly improving testing efficiency and bench utilization.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a dynamic testing system based on a dual-shaft permanent magnet synchronous dynamometer motor, comprising: a dual-shaft permanent magnet synchronous dynamometer motor, wherein a first shaft extension and a second shaft extension extend from both ends of the rotor respectively; a first coupling and measuring device, connecting the first shaft extension to a first test motor; a second coupling and measuring device, connecting the second shaft extension to a second test motor; a first four-quadrant frequency converter, connecting to and controlling the first test motor; a second four-quadrant frequency converter, connecting to and controlling the second test motor; a third four-quadrant frequency converter, connecting to and controlling the dual-shaft permanent magnet synchronous dynamometer motor; and a measurement and control unit, which is communicatively connected to the first, second, and third four-quadrant frequency converters and the first and second couplings and measuring devices, for data acquisition and coordinated control strategies.

[0007] Furthermore, the measurement and control unit integrates a power analysis module, which is configured to independently acquire the three-phase voltage and three-phase current signals of the first test motor and the second test motor, respectively.

[0008] Furthermore, both the first coupling and the measuring device and the second coupling and the measuring device include sensors for independently measuring speed and torque.

[0009] Furthermore, the measurement and control unit is configured to execute a synchronous control strategy, so that the first test motor and the second test motor are in the same motoring state or power generation state during the test.

[0010] Furthermore, the dynamic measurement system also includes an auxiliary synchronous motor connected to the second shaft extension via a rigid coupling, and whose electromagnetic scheme is consistent with that of the dual-shaft extension permanent magnet synchronous dynamometer motor; the measurement and control unit also connects to and controls the auxiliary synchronous motor so that its speed loop is synchronized with that of the dual-shaft extension permanent magnet synchronous dynamometer motor to form a dual-stator drive structure.

[0011] Furthermore, the first coupling and measuring device and the second coupling and measuring device include a coupling, which is a diaphragm coupling.

[0012] A dynamic testing method based on a dual-axis extended permanent magnet synchronous dynamometer motor, applied to a dynamic testing system, is characterized by the following steps: S1: Connecting a first test motor and a second test motor to the two ends of the dual-axis extended permanent magnet synchronous dynamometer motor via couplings and measuring devices; S2: Setting the test conditions through a measurement and control unit and starting the dual-axis extended permanent magnet synchronous dynamometer motor to the target speed; S3: Controlling the first test motor and the second test motor to enter the same working state set by the measurement and control unit, wherein the working state is one of dual-motor state, dual-feed generator state, or dual-no-load state; S4: Independently acquiring the speed and torque signals at both ends through each coupling and measuring device, independently acquiring the electrical signals at both ends through a power analysis module, and processing and analyzing them through the measurement and control unit to complete the synchronous test of the two test motors.

[0013] Furthermore, in step S3, the measurement and control unit monitors the current loop status of the first four-quadrant frequency converter and the second four-quadrant frequency converter in real time. When an abnormal situation is detected in which the operating status of the two motors is inconsistent, a safety self-locking procedure is executed to terminate the test.

[0014] Furthermore, when the power required for testing exceeds the capacity of a single dual-shaft permanent magnet synchronous dynamometer, the dynamic testing method also includes: connecting an auxiliary synchronous motor to the second shaft extension side via a rigid coupling; and synchronously controlling the speed loops of the dual-shaft permanent magnet synchronous dynamometer and the auxiliary synchronous motor via a measurement and control unit, so that they work together as a load for the first tested motor, thereby doubling the test power capacity.

[0015] Compared with existing technologies, the beneficial effects of this invention are: 1. Increased efficiency and outstanding economic benefits: The most direct advantage of this invention is that it can nearly double the testing efficiency. For motor production scenarios that require factory testing, two motors can be tested in a single test cycle, significantly reducing the testing time and energy costs of a single motor and improving the overall utilization rate of production lines and equipment.

[0016] 2. Breakthrough in Capabilities and Broader Testing Range: Through the "dual-stator" power expansion scheme, the system's testing capabilities are no longer limited to the single-unit rated value of the central dynamometer motor. This provides an economical and feasible solution for testing electric drive systems with higher power levels, avoiding the investment of purchasing oversized and expensive dynamometers for testing individual high-power products.

[0017] 3. Flexible Functionality, Multi-functional: One system supports two working modes: the conventional "dual-side synchronous test mode" and the "power extension test mode" for high power applications. Users can flexibly switch between modes according to production tasks, enabling the test platform to handle both rapid testing of batches of small-power motors and performance verification of high-power prototypes, greatly expanding its application scenarios.

[0018] 4. Intelligent control, safe and reliable: The integrated measurement and control unit and the forced synchronization strategy constitute the system's "intelligent safety kernel." It can monitor the status of both sides in real time, prevent dangerous working conditions, and achieve abnormal self-locking, which greatly improves the safety level of automated testing and reduces the risk of damage caused by operational errors or equipment failures.

[0019] 5. Precise Measurement and Independent Data: The end-to-end independent measurement design, from mechanical to electrical quantities, ensures that data from two motors tested simultaneously are mutually independent and correspond one-to-one. This provides a solid data foundation for accurately evaluating the performance of each motor, facilitating product quality traceability, and analyzing problems. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them: Figure 1 is a structural schematic diagram of the dynamic testing system based on the dual-axis extended permanent magnet synchronous dynamometer motor (dual-side synchronous test mode); Figure 2 is a structural schematic diagram of the dynamic testing system based on the dual-axis extended permanent magnet synchronous dynamometer motor (power extension test mode).

[0021] The markings in the figure are as follows: 1. Dual-shaft permanent magnet synchronous dynamometer motor; 2. First test motor; 3. Second test motor; 4. First coupling and measuring device; 5. Second coupling and measuring device; 6. Auxiliary synchronous motor. Detailed Implementation

[0022] In the description of this invention, it should be noted that the directional terms such as "center", "horizontal (X)", "longitudinal (Y)", "vertical (Z)", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this invention.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. Thus, the use of "first" and "second" to define a feature may explicitly or implicitly include one or more of that feature. In the description of this invention, "several" or "a number" means two or more, unless otherwise explicitly specified.

[0024] A dynamic testing system based on a dual-shaft permanent magnet synchronous dynamometer motor 1, as shown in Figures 1-2, includes: a dual-shaft permanent magnet synchronous dynamometer motor 1, with a first shaft extension and a second shaft extension extending from both ends of its rotor; a first coupling and measuring device 4, connecting the first shaft extension to a first test motor 2; a second coupling and measuring device 5, connecting the second shaft extension to a second test motor 3; a first four-quadrant frequency converter, connecting and controlling the first test motor 2; a second four-quadrant frequency converter, connecting and controlling the second test motor 3; a third four-quadrant frequency converter, connecting and controlling the dual-shaft permanent magnet synchronous dynamometer motor 1; and a measurement and control unit, which is communicatively connected to the first, second, and third four-quadrant frequency converters and the first and second couplings and measuring device 5, for data acquisition and coordinated control strategies.

[0025] The core of this invention lies in using a dual-shaft extended permanent magnet synchronous motor as the central dynamometer and load unit, replacing the single-function auxiliary motor in the traditional "one-to-one" test bench. Because its rotor is coaxial, the dual-shaft extended motor can ensure that the output speeds at both ends are strictly synchronized, providing a physical basis for independent testing on both sides. By connecting the test motor to the two shaft extension ends respectively and supplementing it with independent measurement and control circuits, an integrated platform that can perform two independent tests simultaneously is constructed.

[0026] Preferably, the measurement and control unit integrates a power analysis module, which is configured to independently acquire the three-phase voltage and three-phase current signals of the first test motor 2 and the second test motor 3. Specifically, this solution employs a power analysis module with multi-channel independent acquisition capabilities, connecting the three-phase input lines of the left and right motors to independent measurement channels, thereby achieving isolation at the data source and ensuring the independence and accuracy of various electrical parameters (such as voltage, current, power, and power factor) measurements. This solves the technical problem of signal interference during dual-sided testing, providing a guarantee for simultaneously acquiring accurate and reliable electrical performance data from two motors.

[0027] Preferably, both the first coupling and measuring device 4 and the second coupling and measuring device 5 include sensors for independently measuring speed and torque. Specifically, in this dynamic testing system, the dual-shaft dynamometer motor serves as a common speed reference, but the loads (torques) at its two ends may differ. High-precision torque and speed sensors are installed on the left and right transmission chains respectively. The sensors measure the relative torque between the corresponding shaft extensions of the tested motor and the dual-shaft dynamometer motor, while the speed measurement value is compared and verified with the dynamometer speed reference. This achieves completely independent and synchronous measurement of the mechanical characteristics of the two tested motors, accurately reflecting their dynamic responses under the same or different load conditions, and meeting the testing requirements for complex operating conditions.

[0028] Preferably, the measurement and control unit is configured to execute a synchronous control strategy, so that the first test motor 2 and the second test motor 3 are in the same electric state or power generation state during the test. Specifically, through top-level control logic constraints, the risk of control instability caused by the cancellation of torque on both sides is fundamentally eliminated, ensuring the safety and controllability of the entire test process, and guaranteeing the stability and repeatability of the test data.

[0029] Preferably, the dynamic testing system further includes an auxiliary synchronous motor 6 connected to the second shaft extension via a rigid coupling, and whose electromagnetic scheme is consistent with that of the dual-shaft permanent magnet synchronous dynamometer 1. The measurement and control unit also connects to and controls the auxiliary synchronous motor 6, synchronizing its speed loop with that of the dual-shaft permanent magnet synchronous dynamometer 1 to form a dual-stator drive structure. This is the power expansion mode of the present invention. When it is necessary to test a motor whose power exceeds the capacity of a single dual-shaft dynamometer, a motor of the same specification is rigidly connected to one end (such as the second shaft extension end). Through the high-precision synchronization algorithm of the measurement and control unit, the controllers of the two motors execute completely consistent speed commands, as if the two stator windings of a single rotor work together. According to the principle of "dual-stator" motors, under ideal conditions, their combined output capacity can reach twice that of a single motor. Thus, by cleverly using a "1+1" parallel coordination method, the limitation of the power limit of a single dynamometer on the test platform capacity is broken, greatly expanding the test range of the test bench, realizing the function of "testing large motors on a small platform", and improving the investment value and applicability of the equipment.

[0030] Preferably, the first coupling and measuring device 4 and the second coupling and measuring device 5 include a coupling, which is a diaphragm coupling. Specifically, the use of a diaphragm coupling can effectively absorb installation alignment errors and micro-deformation during operation, reduce vibration and stress in the transmission chain, protect the precision torque and speed sensor, ensure smooth power transmission and accurate measurement signals, and meet the requirements of high precision and long service life in industrial applications.

[0031] A dynamic testing method based on a dual-axis extended permanent magnet synchronous dynamometer motor 1, applied to a dynamic testing system, is characterized by the following steps: S1: Connecting a first test motor 2 and a second test motor 3 to both ends of the dual-axis extended permanent magnet synchronous dynamometer motor 1 via couplings and measuring devices; S2: Setting the test conditions through a measurement and control unit and starting the dual-axis extended permanent magnet synchronous dynamometer motor 1 to the target speed; S3: Controlling the first test motor 2 and the second test motor 3 to enter the same working state set by the measurement and control unit, wherein the working state is one of dual-motor state, dual-feed generator state, or dual-no-load state; S4: Independently acquiring the speed and torque signals at both ends through each coupling and measuring device, independently acquiring the electrical signals at both ends through a power analysis module, and processing and analyzing them through the measurement and control unit to complete the synchronous test of the two test motors.

[0032] Preferably, in step S3, the measurement and control unit monitors the current loop status of the first four-quadrant frequency converter and the second four-quadrant frequency converter in real time. When an abnormal situation is detected in which the operating status of the two motors is inconsistent, a safety self-locking procedure is executed to terminate the test.

[0033] Preferably, when the power required for testing exceeds the capacity of a single dual-shaft permanent magnet synchronous dynamometer 1, the dynamic testing method further includes: connecting an auxiliary synchronous motor 6 to the second shaft extension side via a rigid coupling; and synchronously controlling the speed loops of the dual-shaft permanent magnet synchronous dynamometer 1 and the auxiliary synchronous motor 6 through a measurement and control unit, so that they work together as a load for the first tested motor 2, thereby doubling the test power capacity.

[0034] Dual-sided synchronous testing mode: The dynamic testing system in this embodiment includes a dual-axis permanent magnet synchronous dynamometer motor 1. Its left side is connected to a first test motor 2 via a first diaphragm coupling and a measuring device, and its right side is connected to a second test motor 3 via a second diaphragm coupling and a measuring device. The first test motor 2, the second test motor 3, and the dual-axis permanent magnet synchronous dynamometer motor 1 are driven and controlled by first, second, and third four-quadrant frequency converters, respectively. An integrated measurement and control unit (typically an industrial computer or PLC) is connected to the first, second, and third four-quadrant frequency converters, as well as the first coupling and measuring device 4 and the second coupling and measuring device 5, via a communication network (such as CAN / EtherCAT).

[0035] The measurement and control unit has a built-in power analysis module, whose voltage and current probes are connected to the U, V, and W three-phase input terminals of the first test motor 2 and the second test motor 3, respectively, to achieve six independent electrical signal acquisition. The torque and speed sensor signals built into the first coupling and measuring device 4 and the second coupling and measuring device 5 are also connected to the measurement and control unit.

[0036] During testing, the operator sets the test items (such as peak torque test) in the measurement and control unit software interface. The measurement and control unit first controls the dual-axis extended permanent magnet synchronous dynamometer motor 1 to accelerate to a predetermined speed n0 via the third-fourth-quadrant frequency converter controller. Then, according to the settings, it sends commands to the first-fourth-quadrant frequency converter controller and the second-fourth-quadrant frequency converter controller, causing the first test motor 2 and the second test motor 3 to simultaneously enter either motoring or generating states. During the test, the first coupling and measuring device 4 measure the relative torque τ1 and speed n1 (n1 should be equal to n0) between the first test motor 2 and the dual-axis extended permanent magnet synchronous dynamometer motor 1, while the second-fourth-quadrant frequency converter controller measures τ2 and n2. The power analysis module simultaneously records the voltage, current, power, and other electrical parameters of the first test motor 2 and the second test motor 3. The measurement and control unit integrates all data to complete this performance test of the first test motor 2 and the second test motor 3 in one go.

[0037] Throughout the process, the measurement and control unit monitors the current loop status fed back by the first and second quadrant frequency converters in real time. Once a trend of motor torque on one end and generator torque on the other end is detected (i.e., asynchronous operation), the measurement and control unit will immediately issue an emergency stop command to all controllers, activate the safety self-locking, and prevent the system from going out of control.

[0038] Power Extension Test Mode for High Power: When testing a high-power motor under test, a power extension scheme is adopted. In this mode, the system configuration includes: a dual-axis extended permanent magnet synchronous dynamometer 1, with the motor under test connected to its left side and an auxiliary synchronous motor 6 connected to its right side via a rigid coupling (the electromagnetic design of the auxiliary synchronous motor 6 is consistent with that of the dual-axis extended permanent magnet synchronous dynamometer 1). The dual-axis extended permanent magnet synchronous dynamometer 1 and the auxiliary synchronous motor 6 are controlled by the third and fourth quadrant frequency converters and the second and fourth quadrant frequency converters, respectively, while the high-power motor under test is controlled by the first and fourth quadrant frequency converters. The measurement and control unit is responsible for overall control.

[0039] During testing, the measurement and control unit uses a high-speed synchronous control algorithm to ensure that the speed loop commands of the third and fourth quadrant frequency converters are completely consistent. This allows the dual-axis permanent magnet synchronous dynamometer 1 and the auxiliary synchronous motor 6 to operate in strict synchronization, like two stator windings of a single motor, serving together as either the load (when the high-power test motor is motoring) or the drive source (when the high-power test motor is generating electricity) for the high-power test motor. Because the dual-axis permanent magnet synchronous dynamometer 1 and the auxiliary synchronous motor 6 work together, the system can provide approximately twice the torque and power capacity of a single dual-axis permanent magnet synchronous dynamometer 1, thus meeting the testing requirements for the high-power test motor. At this time, the measuring device on the right measures the torque and speed of the auxiliary synchronous motor 6, or it can be removed if needed, and the measurement and control unit can estimate the speed based on feedback from the second and fourth quadrant frequency converters.

[0040] Advantages: 1. Increased efficiency and significant economic benefits: The most direct advantage of this invention is that it can nearly double the testing efficiency. For motor production scenarios that require factory testing, two motors can be tested in a single test cycle, significantly reducing the testing time and energy costs per motor and improving the overall utilization rate of production lines and equipment.

[0041] 2. Breakthrough in Capabilities and Broader Testing Range: Through the "dual-stator" power expansion scheme, the system's testing capabilities are no longer limited to the single-unit rated value of the central dynamometer motor. This provides an economical and feasible solution for testing electric drive systems with higher power levels, avoiding the investment of purchasing oversized and expensive dynamometers for testing individual high-power products.

[0042] 3. Flexible Functionality, Multi-functional: One system supports two working modes: the conventional "dual-side synchronous test mode" and the "power extension test mode" for high power applications. Users can flexibly switch between modes according to production tasks, enabling the test platform to handle both rapid testing of batches of small-power motors and performance verification of high-power prototypes, greatly expanding its application scenarios.

[0043] 4. Intelligent control, safe and reliable: The integrated measurement and control unit and the forced synchronization strategy constitute the system's "intelligent safety kernel." It can monitor the status of both sides in real time, prevent dangerous working conditions, and achieve abnormal self-locking, which greatly improves the safety level of automated testing and reduces the risk of damage caused by operational errors or equipment failures.

[0044] 5. Precise Measurement and Independent Data: The end-to-end independent measurement design, from mechanical to electrical quantities, ensures that data from two motors tested simultaneously are mutually independent and correspond one-to-one. This provides a solid data foundation for accurately evaluating the performance of each motor, facilitating product quality traceability, and analyzing problems.

[0045] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A dynamic measurement system based on a dual-shaft extended permanent magnet synchronous dynamometer motor, characterized in that, include: A dual-shaft permanent magnet synchronous dynamometer has a first shaft extension and a second shaft extension extending from both ends of its rotor, respectively; a first coupling and a measuring device connect the first shaft extension to a first motor under test; a second coupling and a measuring device connect the second shaft extension to a second motor under test; a first four-quadrant frequency converter connects to and controls the first motor under test; a second four-quadrant frequency converter connects to and controls the second motor under test; a third four-quadrant frequency converter connects to and controls the dual-shaft permanent magnet synchronous dynamometer; and a measurement and control unit is communicatively connected to the first, second, and third four-quadrant frequency converters, as well as the first and second couplings and the measuring device, for data acquisition and coordinated control strategies.

2. The dynamic measurement system based on a dual-axis extended permanent magnet synchronous dynamometer motor according to claim 1, characterized in that: The measurement and control unit integrates a power analysis module, which is configured to independently acquire the three-phase voltage and three-phase current signals of the first test motor and the second test motor.

3. The dynamic measurement system based on a dual-axis extended permanent magnet synchronous dynamometer motor according to claim 1, characterized in that: Both the first coupling and the measuring device and the second coupling and the measuring device include sensors for independently measuring speed and torque.

4. The dynamic measurement system based on a dual-axis extended permanent magnet synchronous dynamometer motor according to claim 1, characterized in that: The measurement and control unit is configured to execute a synchronous control strategy, so that the first test motor and the second test motor are in the same motoring state or power generation state during the test.

5. A dynamic measurement system based on a dual-axis extended permanent magnet synchronous dynamometer motor according to claim 1, characterized in that: The dynamic measurement system also includes an auxiliary synchronous motor connected to the second shaft extension via a rigid coupling, and whose electromagnetic scheme is consistent with that of the dual-shaft extension permanent magnet synchronous dynamometer motor; the measurement and control unit also connects to and controls the auxiliary synchronous motor so that its speed loop is synchronized with that of the dual-shaft extension permanent magnet synchronous dynamometer motor to form a dual-stator drive structure.

6. A dynamic measurement system based on a dual-axis extended permanent magnet synchronous dynamometer motor according to any one of claims 1-5, characterized in that: The first coupling and measuring device and the second coupling and measuring device include a coupling, which is a diaphragm coupling.

7. A dynamic testing method based on a dual-axis extended permanent magnet synchronous dynamometer motor, applied to the dynamic testing system as described in any one of claims 1-6, characterized in that, Includes the following steps: S1: Connect the first and second test motors to the two ends of the dual-shaft extended permanent magnet synchronous dynamometer motor via couplings and measuring devices, respectively; S2: Set the test conditions through the measurement and control unit and start the dual-shaft extended permanent magnet synchronous dynamometer motor to the target speed; S3: Control the first and second test motors to enter the same working state set by the measurement and control unit, wherein the working state is one of dual-motor state, dual-feed generator state, or dual-no-load state; S4: Independently collect the speed and torque signals at both ends through each coupling and measuring device, independently collect the electrical signals at both ends through the power analysis module, and process and analyze them through the measurement and control unit to complete the synchronous test of the two test motors.

8. The dynamic testing method according to claim 7, characterized in that: In step S3, the measurement and control unit monitors the current loop status of the first four-quadrant frequency converter and the second four-quadrant frequency converter in real time. When an abnormal situation is detected in which the operating status of the two motors is inconsistent, a safety self-locking procedure is executed to terminate the test.

9. The dynamic testing method according to claim 7, characterized in that: When the power required for testing exceeds the capacity of a single dual-shaft permanent magnet synchronous dynamometer, the dynamic testing method further includes: connecting an auxiliary synchronous motor to the second shaft extension side via a rigid coupling; and synchronously controlling the speed loops of the dual-shaft permanent magnet synchronous dynamometer and the auxiliary synchronous motor via a measurement and control unit, so that they work together as a load for the first motor under test, thereby doubling the test power capacity.

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