Half-direct drive motor and reducer test system and method

Abstract

The application relates to a semi-direct drive motor and reducer testing system and method. The application is used for testing semi-direct drive motors and reducers of mining equipment. The system comprises a power supply and distribution system, a motor loading system, a reducer loading system and a measurement and control system. The power supply and distribution system provides adjustable test power supply of different voltage grades for the tested parts through a transformer and a voltage regulator. The motor loading system comprises load motors connected with each tested motor, and the load motors are connected with frequency converters with network feed function. The reducer loading system adopts multi-transmission DC bus feedback technology, and comprises pulse rectifier units connected with the power supply and distribution system and a common DC bus, test reducers connected with each tested reducer, loading motors and drive motors connected with the test reducers, inverters connected with the drive motors and the loading motors, and the inverters are connected with the common DC bus. The measurement and control system collects and automatically adjusts test parameters, and realizes closed-loop control. The application can feedback energy when testing the motor and the reducer, and can automatically adjust the power supply voltage and the load.

Description

Technical Field

[0001] This invention relates to the field of testing technology for mining equipment; specifically, this invention relates to a testing system and method for a semi-direct drive motor and reducer. Background Technology

[0002] As my country places increasing emphasis on the reliability and safety of mining equipment, the demand for loading test devices for various mining electromechanical transmission equipment is also growing. Key electromechanical components in existing mining equipment mainly include motors and reducers. Performance tests are required for these key components to ensure their reliability.

[0003] Currently, domestic and international gearbox testing systems only test individual gearboxes and lack the capability to simultaneously test semi-direct drive motors. Since many gearbox manufacturers are currently engaged in the production and research of semi-direct drive motors, there is an urgent need for supporting testing equipment. Summary of the Invention

[0004] In view of this, the present invention provides a semi-direct drive motor and reducer testing system and method, thereby solving or at least alleviating one or more of the above-mentioned problems and other problems existing in the prior art.

[0005] To achieve the aforementioned objectives, a first aspect of the present invention provides a semi-direct drive motor and reducer testing system, wherein the system is used to test semi-direct drive motors and reducers of mining equipment, comprising:

[0006] The power supply and distribution system includes a transformer and a voltage regulator. The input terminals of the transformer and the voltage regulator are connected to the power grid, and the output terminals are connected to test systems of different voltage levels to provide an adjustable test power supply for the test specimen.

[0007] The motor loading system includes a semi-direct drive motor as the test motor, a load motor, and a frequency converter. The output terminal of the power supply and distribution system is connected to the test motor. Each test motor is connected to a corresponding load motor. The load motor is connected to a corresponding frequency converter. The frequency converter is connected to the output terminal of the power supply and distribution system and has the function of feeding the electrical energy generated by the load motor back to the power grid through the power supply and distribution system.

[0008] The speed reducer loading system includes a speed reducer under test, a test speed reducer, a drive motor, a loading motor, a pulse rectifier unit, and multiple inverters. The pulse rectifier unit is connected to the output terminal of the power supply and distribution system and a common DC bus. Each inverter is connected to the common DC bus. Each speed reducer under test is connected to a corresponding drive motor through a corresponding test speed reducer. Each speed reducer under test is also connected to a corresponding loading motor. Each drive motor and loading motor are connected to their respective inverters. The electrical energy generated by the loading motor is fed back to the common DC bus through the corresponding inverter and reused by the drive motor.

[0009] A measurement and control system is used to collect and automatically adjust test parameters during the test, and to perform closed-loop control of the test process. The test parameters include power supply voltage and load.

[0010] In the system described above, optionally, the system supports simultaneous loading tests on multiple test motors, and supports loading tests on semi-direct drive asynchronous motors or permanent magnet synchronous motors, wherein the test motors are electrical explosion-proof products of the same or different explosion-proof ratings.

[0011] The system supports simultaneous loading tests on multiple speed reducers with different power ratings.

[0012] In the system described above, optionally, the transformer is an isolation transformer, and the power supply system supplies power at a maximum voltage of 10kV or higher.

[0013] In the system described above, optionally, the frequency converter is a four-quadrant frequency converter with a grid feeding function, using IGBTs as rectifier units, and the output terminal of the frequency converter uses an LCL filter.

[0014] In the system described above, optionally, the measurement and control system performs closed-loop control based on PI regulation. The closed-loop control method includes: setting a target value for the test parameter, automatically adjusting the test parameter according to the target value, and maintaining the test parameter stable at the target value.

[0015] In the system described above, optionally, when the measurement and control system controls the load, the load value is calibrated by either torque calibration or power supply current calibration.

[0016] In the system described above, optionally, the measurement and control system has protection functions including overload protection for the power supply under test, overload protection for the frequency converter, motor speed limiting, and over-temperature protection for the frequency converter.

[0017] To achieve the aforementioned objective, a second aspect of the present invention provides a method for testing a semi-direct drive motor and a reducer, wherein the method is based on a system as described in any of the preceding first aspects, and the method includes:

[0018] The power supply and distribution system provides the test specimen with a multi-voltage level and adjustable test power.

[0019] Configure the motor loading system and the reducer loading system such that one or more test motors are connected to the corresponding load motors, and one or more test reducers are connected to the corresponding auxiliary reducers between the drive motor and the loading motor.

[0020] A loading test was conducted on the tested motor and the tested reducer. During the test, the test parameters were collected and recorded. Based on the target parameter values ​​and the collected parameter values, PI adjustment was performed to achieve closed-loop control of the test parameters.

[0021] In the method described above, optionally, the step of performing a load test on the motor includes:

[0022] Power from the grid is supplied to the tested motor via the power supply and distribution system to start the tested motor.

[0023] The tested motor drives the load motor to generate electricity.

[0024] The speed and torque of the load motor are controlled by the frequency converter, so that the load motor operates in the generator state and applies a set load to the test motor.

[0025] The inverter converts the electrical energy generated by the load motor into three-phase AC power that meets the grid requirements and then feeds it back to the grid.

[0026] In the method described above, optionally, the step of performing a load test on the reducer includes:

[0027] The AC power supplied by the power supply and distribution system is rectified into DC power and output to the common DC bus.

[0028] The operating parameters of the inverter connected to the drive motor are set, including at least one of the following: speed mode, speed setpoint, acceleration / deceleration time, and speed and torque limit range;

[0029] Set the operating parameters of the inverter connected to the load motor, including at least one of torque mode, torque setpoint, acceleration / deceleration time, speed and torque limit range, wherein the initial value of the torque setpoint is zero;

[0030] Start the inverter connected to the drive motor, so that the drive motor drives the test reducer to rotate;

[0031] Start the inverter connected to the load motor, and adjust the torque of the load motor during the test so that the load motor is in a power generation state and applies a set load to the test reducer;

[0032] The electrical energy generated by the loading motor is fed back to the common DC bus through the inverter connected to the loading motor, and the inverter connected to the drive motor draws electrical energy from the common DC bus to realize the reuse of electrical energy.

[0033] Record the torque and speed of the tested reducer during the test;

[0034] After the loading test is completed, the torque setpoint of the loading motor is set to zero to unload the load, and then the power supply to the drive motor is stopped.

[0035] The semi-direct drive motor and reducer testing system of the present invention can perform energy feedback when testing motors and reducers, and can achieve adaptive adjustment of power supply voltage and load.

[0036] The present invention further provides a test method for semi-direct drive motors and reducers, which also has the above-mentioned advantages. Attached Figure Description

[0037] The disclosure of this invention will become more apparent from the accompanying drawings. It should be understood that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings:

[0038] Figure 1 This is a schematic diagram of the power supply and distribution system of an embodiment of the semi-direct drive motor and reducer testing system of the present invention.

[0039] Figure 2 This is a schematic diagram of the motor loading system of an embodiment of the semi-direct drive motor and reducer testing system of the present invention.

[0040] Figure 3 This is a schematic diagram of the reducer loading system according to an embodiment of the semi-direct drive motor and reducer testing system of the present invention.

[0041] Figure 4 This is a schematic diagram of the speed reducer loading test process, which is an embodiment of the semi-direct drive motor and speed reducer test method of the present invention. Detailed Implementation

[0042] Referring to the accompanying drawings and specific embodiments, the structure, composition, features, and advantages of the semi-direct drive motor and reducer testing system and method of the present invention will be described below by way of example. However, all descriptions should not be construed as limiting the present invention in any way.

[0043] Furthermore, for any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature shown or implied in the various figures, the present invention still allows for any combination or deletion of these technical features (or their equivalents) without any technical obstacle, and thus these further embodiments according to the present invention should also be considered within the scope of this description.

[0044] It should also be noted that 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 indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0045] An embodiment of the semi-direct drive motor and reducer testing system of the present invention includes a power supply and distribution system, a motor loading system, a reducer loading system, and a measurement and control system. Exemplarily, this testing system performs loading tests on three 1000kW semi-direct drive motors, one 750kW reducer, and one 350kW reducer.

[0046] Figure 1-3 The circuit structures of the power supply and distribution system, the motor loading system, and the reducer loading system are shown respectively.

[0047] Reference Figure 1 The power supply and distribution system of this embodiment includes a voltage regulator with a capacity of 2000kVA, an input voltage of 10kV, and an output voltage adjustable from 0 to 10.5kV, and a transformer with a capacity of 2500kVA, an input voltage of 10kV, and an output voltage of 3300V (hereinafter referred to as the first transformer). It also includes a transformer (not shown) with a capacity of 1600kVA, an input voltage of 10kV, and an output voltage of 690V (hereinafter referred to as the second transformer), and is equipped with incoming and outgoing line cabinets and starter cabinets of various voltage levels, which can provide 1140V, 3300V, or 10kV power supply to the tested semi-direct drive motor.

[0048] For example, the voltage regulator is connected to the power grid via disconnect switch K2 and to two output branches via AC contactor KM1. During the test, K2 closes and KM1 closes, allowing the voltage regulator to adjust the 10kV AC input from the power grid to an adjustable output voltage within the range of 0-10.5kV, which is then fed into the two output branches. Each branch passes through a low-voltage current transformer (LVCT1 or LVCT2) and a circuit breaker (DJX1 or DJX2), ultimately leading to output terminals A and B. Simultaneously, the first transformer is connected to the power grid via disconnect switch K1. During the test, K1 closes, and the first transformer steps down the 10kV AC input from the power grid to 3300V, which then passes through a low-voltage current transformer LVCT3 and a circuit breaker DJX3 before being led to output terminal C. This forms three output terminals (A, B, and C) with different voltage levels and measurement and protection functions, for subsequent connection to the device under test.

[0049] Figure 1 The dashed box also shows the three frequency converters in the motor loading system and the load units they drive. The input voltage of the frequency converters is 690V, provided by the aforementioned second transformer. Each load motor is led out through terminals JZ1, JZ2, and JZ3 for subsequent connection to the motor under test.

[0050] Reference Figure 2 In this embodiment, the motor loading system uses an AC generator set as the load, and the load energy is fed back to the power grid using a multi-drive four-quadrant frequency converter. At the same time, the frequency converter device is used to control the load generator set to complete the loading and load adjustment.

[0051] like Figure 2 As shown, this motor loading system can simultaneously test three semi-direct drive motors (M). Each semi-direct drive motor is connected to the aforementioned output terminals (A, B, or C) and wiring terminals (JZ1, JZ2, or JZ3). Three sets of four-quadrant frequency converters are used for loading, each with an input voltage of 690V, driving three 1100kW motors. These three AC motors serve as load motors, simulating the mechanical load driven by the tested motors in actual applications. Since the tested semi-direct drive motors are electrical explosion-proof products of different grades, AC side feedback is used to avoid introducing additional risks to the DC bus in the explosion-proof area, improving system safety, and simultaneously achieving efficient energy feedback to the grid, reducing energy consumption and heat generation.

[0052] The principle of this motor loading system is as follows: energy from the power grid starts the tested motor via the starter cabinet. The tested motor drives the load motor to generate electricity, which is then fed back to the power grid through a frequency converter with grid feeding function. The frequency converter uses IGBTs (Insulated Gate Bipolar Transistors) as the rectifier unit. By adjusting the internal program of the frequency converter, the load unit completes the loading and load regulation, ensuring that the load motor operates in a generating state during the test. The frequency converter converts the electrical energy into three-phase AC power that meets the requirements of the power grid, creating an internal energy feedback loop in the system. Through frequency converter control, the load motor can operate at various speeds and torque conditions, thus enabling the testing of the tested motor under various load conditions.

[0053] Optionally, an LCL filter is installed at the output of the frequency converter. This is because, in this embodiment, the frequency converter is loaded using a four-quadrant frequency converter. As a strong source of interference, the frequency converter interferes with surrounding equipment and data signals during operation through spatial and cable coupling. The measurement circuit includes separate measurements of the input and output of the multi-drive frequency converter, and the input power frequency contains abundant high-frequency harmonics. Therefore, an LCL filter is installed on the frequency converter. An LCL filter is a passive filter circuit composed of two inductors (L) and one capacitor (C), widely used at the output of power electronic equipment. Its main function is to suppress high-frequency harmonics and improve power quality. The LCL filter effectively filters out high-frequency noise in the power system through the impedance characteristics of the inductor and the capacitive reactance characteristics of the capacitor, thereby improving the overall system performance. Optionally, harmonic interference can also be reduced by adding isolation transformers, repeated grounding, optimizing communication strategies, and proper wiring.

[0054] Reference Figure 3 The reducer loading system in this embodiment can perform loading tests on 750kW and 350kW reducers through different combinations of frequency converter (frequency converter cabinet) modules. Since the reducer test involves a large starting inertia that is independent of voltage level, multi-drive DC bus feedback technology is adopted to achieve internal energy circulation, significantly reducing energy consumption and improving dynamic response performance.

[0055] like Figure 3As shown, the incoming line cabinet is connected to the power supply line, receiving 690V power from the power distribution system and outputting it to the pulse rectifier unit. The pulse rectifier unit has a rated power of 1000kW, rectifying the 690V AC power input from the incoming line cabinet into DC power and outputting it to the common DC bus. The common DC bus is connected to each inverter cabinet. The pulse rectifier unit cabinet, the common DC bus, and the inverter cabinets are combined to form a frequency converter cabinet. The test channels of each reducer under test are parallel to each other. Each test channel passes sequentially through the drive motor (M1 or M3), drive torque meter, auxiliary reducer, load reducer (reducer under test), load torque meter, and load motor (M2 or M4). Each drive motor (M1, M3) and load motor (M2, M4) is connected to its respective inverter cabinet to achieve precise adjustment of speed and torque, meeting the performance testing requirements of reducers under multiple operating conditions. The auxiliary reducer is paired with the reducer under test to form a transmission chain, transmitting torque and simulating the meshing and load conditions in actual operating conditions, ensuring that the test conditions are real and effective. Torque meters are used to measure torque and speed on drive shafts in real time, providing crucial data for evaluating the performance, efficiency, and load characteristics of the gearbox under test.

[0056] The principle of the reducer loading system is as follows: the drive motor and the loading motor are driven by two sets of inverters of frequency converter. The two sets of inverters share a set of rectifier modules. The drive motor drives the test reducer through the test reducer. The test reducer then drives the loading motor to rotate. The electrical energy generated by the rotation of the loading motor is fed back through the common DC bus and reused.

[0057] The measurement and control system (not shown in the figure) in this embodiment includes a computer-controlled measurement system, a PLC control system, etc., and has fully automatic closed-loop regulation capability, enabling dynamic coordinated control of power supply voltage and load. Its core control logic adopts a closed-loop control process including setting target value, automatic adjustment, and automatic steady-state maintenance.

[0058] In terms of power supply voltage control, the target value of the required output voltage can be manually set first, and the system will then start the automatic voltage boosting and bucking program, adjusting the output in real time through the voltage regulator or frequency converter. This process is driven by the built-in PI (proportional-integral) regulator, which dynamically calculates and outputs the optimal control quantity based on the deviation between the current voltage feedback value and the target value, until the voltage stabilizes near the set value and continues to maintain this state, effectively suppressing voltage drift caused by grid fluctuations or load changes.

[0059] The same process applies to load control. The load target can be selected as either torque or motor current; these two calibration modes are suitable for mechanical performance testing and electrical characteristic testing scenarios, respectively. Based on the selected target value, the system automatically adjusts the torque output of the load motor / loading motor to achieve smooth load increases and decreases. For example, in a motor loading system, the torque of the corresponding load motor is adjusted via a frequency converter; in a reducer loading system, the torque of the corresponding loading motor is adjusted via an inverter cabinet. This adjustment process is also completed in a closed loop by a PI controller. The proportional term (P) quickly responds to deviations, and the integral term (I) eliminates steady-state errors, ensuring that the load value accurately tracks the setpoint. Furthermore, the system is equipped with a "one-click unloading" function, which can instantly reduce the load to zero in case of emergencies or at the end of the test, ensuring the safety of equipment and personnel. Unloading can be achieved by setting the torque setpoint of the load motor / loading motor to zero.

[0060] Through the aforementioned closed-loop control architecture based on PI regulation, the system achieves independent, precise, and stable regulation of voltage and load, providing highly reproducible test conditions for the device under test.

[0061] Optionally, the measurement and control system also adopts the closed-loop control method described above for other test parameters. For example, when using a regenerative inverter (an inverter with a grid feeding function) to drive a regenerative motor (load motor / load motor), the system achieves precise speed regulation through a closed-loop control process of setting a target speed, automatically increasing or decreasing the speed, and automatically maintaining steady state. In this process, the PI regulator tracks the speed deviation in real time and dynamically adjusts the output to ensure that the speed is stable at the set value. When driving the test motor, the speed control is performed by setting a target frequency, automatically increasing or decreasing the frequency, and automatically maintaining steady state (PI regulation), which is suitable for different types of motor drive requirements.

[0062] The control software can be enhanced with torque and current limiting functions, allowing users to flexibly set upper limits for torque or current to prevent equipment overload. The system is also equipped with multiple protection mechanisms, including overload protection for the tested power supply, overload protection for the regenerative inverter, over-limit protection for the motor speed, and over-temperature protection for the regenerative inverter, comprehensively improving the safety and reliability of the testing process.

[0063] The tested semi-direct drive motor can be an asynchronous motor or a permanent magnet synchronous motor. The measurement and control system can support manual configuration or automatic identification of motor parameters through software. After the frequency converter is powered on, it can automatically identify the electrical parameters of the connected motor and optimize the control strategy accordingly to improve drive performance.

[0064] To meet the technical requirements of various test projects, the measurement and control system coordinates the output of the digital drive power supply and the electronic analog load, synchronously acquiring the electrical parameters (such as voltage, current, and power) and non-electrical parameters (such as torque, speed, and temperature) of the test device. Within the specified test cycle, it implements multi-variable closed-loop control on key parameters such as the input torque, speed, and output voltage, current, and power of the test motor, completing the entire test process fully automatically. In this embodiment, the control accuracy of parameters such as torque, voltage, current, power, and frequency can reach ±0.2%.

[0065] This embodiment enables automated testing, significantly reducing the tedious operations required by testing personnel. During the test, the measured parameters of the frequency converter and the test piece are collected in real time, and the frequency converter's loading data is adjusted promptly through data analysis. The computer monitors the parameters in real time during the test, making timely predictions and stopping or unloading the equipment when necessary to prevent accidents.

[0066] An embodiment of the semi-direct drive motor and reducer testing method of the present invention can perform highly automated loading tests on semi-direct drive motors and reducers of different specifications. The main steps include: providing test power supplies of multiple voltage levels to the test pieces; configuring a motor loading system and a reducer loading system, and correspondingly connecting one or more semi-direct drive motors and one or more reducers to the test system; performing loading tests on the motors and reducers, collecting and recording test parameters during the test, and performing PI adjustment based on the target parameter values ​​and the collected parameter values ​​to achieve closed-loop control of the test parameters.

[0067] The test power supply of different voltage levels is provided by the 10kV high voltage input from the power grid after conversion and adjustment by equipment such as transformers and voltage regulators. It can flexibly output multiple test voltages such as 1140V, 3300V or 10kV according to the rated voltage requirements of the test piece.

[0068] When there is more than one motor or reducer under test, the test pieces are connected to parallel test channels. For example, in each motor test channel, the input terminal of the motor under test is connected to the output of the power supply section, and the output terminal of the motor under test is connected to the load motor used to apply the load, which is driven by a frequency converter with a grid feeding function; while in each reducer test channel, the output terminal of the reducer under test is connected to the load motor, and the input terminal is connected to the drive motor through a companion reducer under test. Both the drive motor and the load motor are driven by frequency converter modules, and torque meters are installed between the drive motor and the companion reducer under test, and between the load motor and the reducer under test.

[0069] In the above setup, each inverter / inverter module can control and adjust the torque or speed of its connected drive motor, load motor, or loading motor; the test reducer can serve as a standard reference unit, providing stable and controllable input speed and torque, avoiding dynamic fluctuation interference caused by directly using a motor to drive the test reducer; the torque meter can accurately acquire key performance parameters such as efficiency, temperature rise, and vibration, providing crucial data for evaluating the performance, efficiency, and load characteristics of the test piece.

[0070] For example, the frequency conversion unit of the reducer test section can be composed of a unified rectifier unit and multiple inverter units. Each inverter unit drives a motor (drive motor or load motor) connected to it. The rectifier unit and the inverter unit are connected through a common DC bus.

[0071] The above setup takes into account that the tested motors are electrical explosion-proof products of different levels. Therefore, the motor test adopts an AC side feedback design, while the reducer test has a large starting inertia that is independent of the voltage level. Therefore, a multi-drive DC bus feedback design is adopted. The energy feedback path is optimized according to the differences of the tested objects, which not only meets the safety and voltage adaptability requirements of the explosion-proof motor test, but also fully utilizes the energy-saving and dynamic performance advantages of the DC bus under large inertia mechanical loading, achieving a balance between safety, economy and control accuracy.

[0072] The loading test process for each tested motor includes: supplying the tested motor with regulated grid power, starting the tested motor, and driving the load motor to generate electricity; controlling the load motor to operate in generating mode through a frequency converter, and applying a set load to the tested motor by controlling the speed and torque of the load motor; the load motor generates electricity, which is converted by the frequency converter into three-phase AC power that meets the grid requirements, and fed back to the grid.

[0073] The loading test process for each tested reducer includes: rectifying the test power supply (AC) output after grid power regulation into DC power, outputting it to the common DC bus, and supplying it to the motor after inversion by the inverter unit; setting various operating parameters for the drive-side inverter unit and the loading-side inverter unit, with the initial torque setpoint of the loading-side inverter set to zero; starting the drive-side inverter and the loading-side inverter sequentially, so that the drive motor drives the tested reducer to rotate through the test reducer, and the tested reducer drives the loading motor to generate electricity; continuously controlling and adjusting the torque of the loading motor to keep it in the power generation state and applying the set load to the tested reducer; feeding the electrical energy generated by the loading motor back to the common DC bus through the loading-side inverter unit for use by the drive-side inverter unit, realizing the reuse of electrical energy.

[0074] Meanwhile, during the testing of the motor and reducer, parameters such as torque and speed of each test piece were recorded. Furthermore, after completing the loading test, the torque of the load motor / loading motor was adjusted to zero to unload the load, and then the power supply was stopped to complete the test.

[0075] Optionally, the aforementioned frequency converter / frequency converter unit can be flexibly configured to control the motor according to test requirements, including a speed mode for controlling motor speed and a torque mode for controlling motor torque. For example, the frequency converter unit driving the drive motor can be set to operate in speed mode for precise and stable control of the input speed; the frequency converter / frequency converter unit driving the load motor / load motor can be set to torque mode for applying a controllable load.

[0076] Reference Figure 4 For example, the reducer loading test can be performed according to the following specific procedure.

[0077] First, begin test preparation by selecting the control method and confirming the test piece; then, place the switching switch on the drive motor side and use the drive motor as the power input.

[0078] Set the acceleration / deceleration time, maximum and minimum speed values ​​of inverter 2 (drive-side inverter), set its control mode to speed mode, and set the torque limit value and speed setpoint value. Confirm that the inverter 2 ready signal is normal. Then set inverter 1 (load-side inverter) to torque mode, configure its acceleration / deceleration time, maximum and minimum speed values ​​and torque limit value, and set the initial torque setpoint value to 0. Check the inverter 1 ready signal.

[0079] After preparation, the inverter 2 cooling fan and drive motor were started sequentially, followed by the zeroing motor to complete the zeroing operation of the torque meter. Then, the inverter 1 cooling fan and loading motor were started, and the torque output of the loading motor was gradually adjusted to achieve the loading test on the reducer under test. During the test, the torque and speed curves of the torque meters on both sides were recorded simultaneously.

[0080] After the test, the torque setpoint of inverter 1 is reset to zero to complete the unloading; after the unloading is completed, inverter 1 is stopped; finally, the high and low voltage switches are disconnected and the drive motor is stopped, and the entire test process is completed.

[0081] In the above process, inverter 2 is set to speed mode to ensure a stable and controllable input speed for the tested reducer. Using closed-loop speed control ensures that even with load changes, the input speed strictly tracks the set value, thus meeting standard test conditions. Inverter 1 is set to torque mode. By applying precise and controllable braking torque, the load on the motor is simulated under actual operating conditions. In torque mode, the output torque is directly controlled, unaffected by minor speed fluctuations, facilitating closed-loop control based on the target torque. It also supports indirect load calibration using current values ​​(since torque is proportional to current).

[0082] Furthermore, parameters such as acceleration / deceleration time, speed range, and torque limit of inverter 2 are set to ensure smooth start-up and shutdown of the drive motor and to provide precise and controllable input speed as required by the test. At the same time, the above parameters of inverter 1 are set, and the initial torque is set to 0, in order to establish a safe and controlled loading preparation state for the loading side and prevent impact load from being generated at the moment of start-up.

[0083] By setting the torque setpoint of inverter 1 to zero, the test reducer can be unloaded without impact. After unloading is completed, the loading motor is stopped, the high and low voltage switches are disconnected, and the drive motor is stopped in sequence to ensure that the entire system is safely shut down under no-load conditions, thus ensuring the safety of equipment and personnel.

[0084] Similarly, the specific process of the motor loading test in this embodiment may also include setting the inverter control mode, parameter values ​​or ranges, loading and unloading operations, etc., and therefore also has the above advantages.

[0085] In summary, the embodiments of the present invention have at least the following advantages: A single testing apparatus can simultaneously meet the full-load testing requirements of both the semi-direct drive motor and the reducer, improving testing efficiency. The loading capacity of the semi-direct drive motor can reach 3*1000kW, and the loading capacity of the reducer can reach 750kW. Simultaneous loading of the same or different loads on multiple drive frequency converters, as needed, simulates the actual load conditions that may occur with multi-drive semi-direct drive motors, which is more conducive to studying the transmission performance of the test piece. During the test, the measured parameters of the loaded frequency converter and the test piece are collected in real time, and the loading data of the frequency converter is adjusted in a timely manner through data analysis. Real-time monitoring of parameters during the test by computer allows for timely prediction of potential problems, and shutdown or unloading is performed when necessary to prevent accidents.

[0086] Some embodiments of the present invention have been successfully applied in actual industrial scenarios to load tests of reducers and semi-direct drive motors of various power levels, verifying their reliability and applicability.

[0087] The technical scope of this invention is not limited to the contents of the above specification. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the scope of this invention.

Claims

1. A testing system for a semi-direct drive motor and reducer, characterized in that, The system is used to test semi-direct drive motors and reducers of mining equipment, including: The power supply and distribution system includes a transformer and a voltage regulator. The input terminals of the transformer and the voltage regulator are connected to the power grid, and the output terminals are connected to test systems of different voltage levels to provide an adjustable test power supply for the test specimen. The motor loading system includes a semi-direct drive motor as the test motor, a load motor, and a frequency converter. The output terminal of the power supply and distribution system is connected to the test motor. Each test motor is connected to a corresponding load motor. The load motor is connected to a corresponding frequency converter. The frequency converter is connected to the output terminal of the power supply and distribution system and has the function of feeding the electrical energy generated by the load motor back to the power grid through the power supply and distribution system. The speed reducer loading system includes a speed reducer under test, a test speed reducer, a drive motor, a loading motor, a pulse rectifier unit, and multiple inverters. The pulse rectifier unit is connected to the output terminal of the power supply and distribution system and a common DC bus. Each inverter is connected to the common DC bus. Each speed reducer under test is connected to a corresponding drive motor through a corresponding test speed reducer. Each speed reducer under test is also connected to a corresponding loading motor. Each drive motor and loading motor are connected to their respective inverters. The electrical energy generated by the loading motor is fed back to the common DC bus through the corresponding inverter and reused by the drive motor. A measurement and control system is used to collect and automatically adjust test parameters during the test, and to perform closed-loop control of the test process. The test parameters include power supply voltage and load.

2. The system as described in claim 1, characterized in that, The system supports simultaneous loading tests on multiple test motors, and supports loading tests on semi-direct drive asynchronous motors or permanent magnet synchronous motors. The test motors are electrical explosion-proof products with the same or different explosion-proof ratings. The system supports simultaneous loading tests on multiple speed reducers with different power ratings.

3. The system as described in claim 1, characterized in that, The transformer is an isolation transformer, and the power supply system supplies power at a maximum voltage of 10kV or higher.

4. The system as described in claim 1, characterized in that, The inverter is a four-quadrant inverter with grid feeding function, using IGBT as the rectifier unit, and the output terminal of the inverter uses an LCL filter.

5. The system as described in claim 1, characterized in that, The measurement and control system performs closed-loop control based on PI regulation. The closed-loop control method includes: setting a target value for the test parameters, automatically adjusting the test parameters according to the target value, and maintaining the test parameters stable at the target value.

6. The system as described in claim 1, characterized in that, When the measurement and control system controls the load, the load value can be calibrated by either torque or power supply current.

7. The system as described in claim 1, characterized in that, The measurement and control system has protection functions including overload protection for the tested power supply, overload protection for the frequency converter, motor speed limiting, and over-temperature protection for the frequency converter.

8. A test method for a semi-direct drive motor and reducer, characterized in that, The method is based on the system described in any one of claims 1-7, and the method includes: The power supply and distribution system provides the test specimen with a multi-voltage level and adjustable test power. Configure the motor loading system and the reducer loading system such that one or more test motors are connected to the corresponding load motors, and one or more test reducers are connected to the corresponding auxiliary reducers between the drive motor and the loading motor. A loading test was conducted on the tested motor and the tested reducer. During the test, the test parameters were collected and recorded. Based on the target parameter values ​​and the collected parameter values, PI adjustment was performed to achieve closed-loop control of the test parameters.

9. The method as described in claim 8, characterized in that, The steps for performing a load test on the motor include: Power from the grid is supplied to the tested motor via the power supply and distribution system to start the tested motor. The tested motor drives the load motor to generate electricity. The speed and torque of the load motor are controlled by the frequency converter, so that the load motor operates in the generator state and applies a set load to the test motor. The inverter converts the electrical energy generated by the load motor into three-phase AC power that meets the grid requirements and then feeds it back to the grid.

10. The method as described in claim 8, characterized in that, The steps for performing a load test on the reducer include: The AC power supplied by the power supply and distribution system is rectified into DC power and output to the common DC bus. The operating parameters of the inverter connected to the drive motor are set, including at least one of the following: speed mode, speed setpoint, acceleration / deceleration time, and speed and torque limit range; Set the operating parameters of the inverter connected to the load motor, including at least one of torque mode, torque setpoint, acceleration / deceleration time, speed and torque limit range, wherein the initial value of the torque setpoint is zero; Start the inverter connected to the drive motor, so that the drive motor drives the test reducer to rotate; Start the inverter connected to the load motor, and adjust the torque of the load motor during the test so that the load motor is in a power generation state and applies a set load to the test reducer; The electrical energy generated by the loading motor is fed back to the common DC bus through the inverter connected to the loading motor, and the inverter connected to the drive motor draws electrical energy from the common DC bus to realize the reuse of electrical energy. Record the torque and speed of the tested reducer during the test; After the loading test is completed, the torque setpoint of the loading motor is set to zero to unload the load, and then the power supply to the drive motor is stopped.

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