A brake unit testing method and system
By using a control system with a low-power motor and frequency converter, precise and automated testing of the braking unit was achieved, solving the problems of high cost, high energy consumption and poor flexibility in the existing technology, and improving the efficiency and accuracy of the test.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SIEMENS ELECTRICAL DRIVES
- Filing Date
- 2026-03-10
- Publication Date
- 2026-07-07
AI Technical Summary
Existing braking unit testing methods are costly, require a large area, consume a lot of energy, are inefficient, and lack flexibility, making it difficult to adjust test conditions flexibly.
A low-power motor and frequency converter are connected to the braking unit. The controller drives the motor to accelerate and perform emergency stop operations, so that energy is fed back to the DC bus. The braking unit is triggered to work after the voltage reaches the threshold. The emergency stop time is adjusted to control the energy consumption, so as to realize the testing of different braking power.
It enables precise and automated testing of braking units, reduces costs and energy consumption, and improves testing flexibility and accuracy, making it suitable for testing at different power points.
Smart Images
Figure CN122345751A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of testing technology for braking units, and more specifically, to a testing method and system for braking units. Background Technology
[0002] In industrial automation and electric drive systems, the braking unit is a crucial component of the frequency converter. When the motor decelerates or stops, its stored kinetic energy is fed back to the DC bus through the frequency converter, causing the DC bus voltage to rise. To protect the frequency converter and the system, the braking unit dissipates this fed-back energy as heat through a braking resistor. Therefore, the performance of the braking unit, especially its braking power, is critical to the stable operation of the system.
[0003] Existing technologies use two motors to test the braking power of the braking unit. This testing method has problems such as high cost, large footprint, high energy consumption, low efficiency, and poor flexibility. Summary of the Invention
[0004] In view of this, this application proposes a braking unit testing method and system to at least solve all or part of the above problems.
[0005] A braking unit testing method, comprising:
[0006] Connect the braking unit to be tested to the DC bus of the frequency converter, and connect the frequency converter to the motor;
[0007] Drive the motor to accelerate to a preset speed;
[0008] An emergency stop operation is performed on the motor, causing the motor to generate energy feedback to the DC bus of the frequency converter, thereby causing the DC bus voltage to rise.
[0009] By monitoring the DC bus voltage, when the DC bus voltage rises to a preset threshold, the braking unit is triggered to work, and the feedback energy is consumed in the braking resistor of the braking unit.
[0010] By adjusting the emergency stop time of the motor, the feedback energy consumed by the braking unit can be controlled, thereby enabling the testing of different braking power of the braking unit under test.
[0011] Furthermore, the method includes: the preset threshold is determined by setting the activation voltage of the braking unit using an analog circuit.
[0012] Furthermore, the method includes: calculating and controlling the motor based on the emergency stop time using the following formula:
[0013] t=W / P
[0014] Where t is the emergency stop time of the motor, W is the kinetic energy of the motor at the preset speed, and P is the braking power of the braking unit under test, which is the braking power required to stop the motor.
[0015] Furthermore, the method includes: the motor is a motor with a power less than the rated braking power of the braking unit under test.
[0016] Furthermore, this method can test the 1200KW braking power of the braking unit under test by using a 200KW motor.
[0017] According to another aspect of this application, a braking unit testing system is also provided, the testing system comprising:
[0018] An electric motor used to store kinetic energy;
[0019] A frequency converter, connected to the motor, is used to drive the motor and receive energy fed back by the motor; a braking unit under test, connected to the DC bus of the frequency converter, is used to consume energy when a trigger signal is received;
[0020] A controller, the controller being configured to:
[0021] The motor is driven to accelerate to a preset speed; an emergency stop operation is performed on the motor, causing it to decelerate rapidly and feed the stored kinetic energy back to the DC bus of the frequency converter, thereby causing the DC bus voltage to rise; by monitoring the DC bus voltage, when the DC bus voltage reaches a preset threshold, a trigger signal is sent to the braking unit under test to activate it, consuming the feedback energy in the braking resistor of the braking unit; by adjusting the emergency stop time of the motor, the feedback energy consumed by the braking unit under test is controlled, thereby enabling the testing of different braking powers of the braking unit under test.
[0022] Furthermore, the controller is configured to set the activation voltage of the braking unit under test via analog circuitry to determine the preset threshold.
[0023] Furthermore, the motor is a motor with a power less than the rated braking power of the braking unit under test.
[0024] Furthermore, the system can test the 1200KW braking power of the braking unit under test using a 200KW motor.
[0025] The braking unit testing method and system based on the embodiments of this application can accurately control the feedback energy consumed by the braking unit by precisely calculating and adjusting the emergency stop time of the motor, thereby achieving accurate testing of different braking power points of the braking unit, improving the accuracy and repeatability of the test. The whole process is completed automatically without frequent equipment switching, making the factory testing of the braking unit more flexible and efficient, and having good versatility.
[0026] Furthermore, the braking unit testing method and system based on the embodiments of this application can be tested using a motor with a power lower than the braking power of the braking unit under test, avoiding the expensive cost and operational difficulties of having two high-power motors supporting each other in the prior art, and also avoiding a large amount of energy loss, making it more energy-efficient and environmentally friendly. Attached Figure Description
[0027] The preferred embodiments of this application will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can more clearly understand the above and other features and advantages of this application, in which:
[0028] Figure 1 This is a structural diagram of a prior art braking unit testing system;
[0029] Figure 2 This is a schematic diagram of the structure of a braking unit testing system according to an embodiment of this application;
[0030] Figure 3 This is a schematic diagram illustrating the steps of a braking unit testing method according to an embodiment of this application;
[0031] The accompanying figure is labeled as follows:
[0032] a1, a2 Two motors in the existing technology testing system
[0033] 1 motor
[0034] 2. Frequency converter
[0035] 3 Rectifier Units
[0036] 100 braking units to be tested
[0037] S10. Connect the braking unit to be tested to the DC bus of a frequency converter, and connect the frequency converter to a motor.
[0038] S20. Drive the motor to accelerate to a preset speed;
[0039] S30. Perform an emergency stop operation on the motor to cause the motor to generate energy feedback to the DC bus of the frequency converter, thereby causing the DC bus voltage to rise.
[0040] S40. By monitoring the DC bus voltage, when the DC bus voltage rises to a preset threshold, the braking unit is triggered to work, and the feedback energy is consumed in the braking resistor of the braking unit.
[0041] S50. By adjusting the emergency stop time of the motor, the feedback energy consumed by the braking unit is controlled, thereby enabling the testing of different braking power of the braking unit under test. Detailed Implementation
[0042] To make the objectives, technical solutions, and advantages of this invention application clearer, the following detailed description of this application is provided in conjunction with the accompanying drawings and embodiments.
[0043] Figure 1 This is a schematic diagram of a system structure for testing the braking power of a braking unit in the prior art;
[0044] like Figure 1 As shown, this type of test system typically uses two motors (a1, a2) to tow the braking unit (100) for testing. In specific testing, this method requires two motors (a1, a2) of the same power level to tow each other, with one motor acting as the drive motor and the other as the load motor.
[0045] It is understandable that this testing method has the following problems:
[0046] 1. High cost: It requires two high-power motors, resulting in a huge investment in equipment.
[0047] 2. Large footprint: High-power motors and supporting equipment are bulky and require a large testing area.
[0048] 3. High energy consumption: During the test, both motors ran continuously, resulting in significant energy loss.
[0049] 4. Inefficiency: The test preparation and execution process is complex and inefficient.
[0050] 5. Poor flexibility: It is difficult to flexibly adjust test conditions to simulate different working conditions. It suffers from high costs, large footprint, high energy consumption, low efficiency, and poor flexibility.
[0051] Therefore, those skilled in the art urgently need to design another simpler, more efficient, lower-cost, and more flexible testing system and method.
[0052] Figure 2 This is a schematic diagram of the structure of a braking unit testing system according to an embodiment of this application;
[0053] like Figure 2As shown, a braking unit testing system according to an embodiment of this application includes a motor 1, a frequency converter 2, and a braking unit 100 to be tested. The motor 1 stores kinetic energy; the frequency converter 2 is connected to the motor 1 and drives the motor 1, receiving energy feedback from the motor 1; the braking unit 100 to be tested is connected to the DC bus of the frequency converter 2 and consumes energy upon receiving a trigger signal. The system also includes a controller (not shown in the figures), configured to:
[0054] The motor is driven to accelerate to a preset speed; an emergency stop operation is performed on the motor, causing it to decelerate rapidly and feed the stored kinetic energy back to the DC bus of the frequency converter, thereby causing the DC bus voltage to rise; by monitoring the DC bus voltage, when the DC bus voltage reaches a preset threshold, a trigger signal is sent to the braking unit under test to activate it, consuming the feedback energy in the braking resistor; by adjusting the emergency stop time of the motor, the feedback energy consumed by the braking unit under test is controlled, thereby enabling the testing of different braking powers of the braking unit under test.
[0055] In some embodiments of this application, the controller may be a programmable logic controller (PLC) or an industrial computer, which integrates the following:
[0056] Voltage monitoring module: Used to acquire the voltage signal of the inverter's DC bus in real time.
[0057] Voltage setting module: used to set a preset threshold, which serves as the activation voltage threshold for the braking unit.
[0058] Calculation and control module: Stores motor parameters (such as moment of inertia), can calculate emergency stop time based on target braking power and motor kinetic energy, and sends speed commands and emergency stop commands to the frequency converter.
[0059] Trigger signal output module: When the DC bus voltage reaches the preset threshold, a trigger signal is sent to the braking unit under test.
[0060] Optionally, a human-machine interface is also included: allowing operators to set preset parameters such as speed and target braking power, and display test results.
[0061] During actual testing, the controller automatically executes a series of operations according to the preset test plan, including motor acceleration, emergency stop, voltage monitoring, and triggering of the braking unit. By adjusting the emergency stop time set in the controller, the system can achieve accurate testing of the braking unit at different power points.
[0062] In some embodiments of this application, the voltage setting module sets the activation voltage of the frequency converter through analog circuitry, specifically through an adjustable potentiometer or a digital-to-analog converter.
[0063] In some embodiments of this application, a motor with a power less than the rated braking power of the braking unit under test may be used.
[0064] Based on the above embodiments, a three-phase asynchronous motor with a rated power of 200KW and a frequency converter with a rated power of 200KW can be used to test a braking unit with a rated braking power of 1200KW.
[0065] like Figure 2 As shown, in some embodiments of this application, components such as rectifier units and capacitors are also included.
[0066] Figure 3 This is a schematic diagram illustrating the steps of a braking unit testing method according to an embodiment of this application.
[0067] like Figure 3 As shown, the method in this embodiment specifically includes:
[0068] S10. Connect the braking unit 100 to be tested to the DC bus of a frequency converter 2, and connect the frequency converter 2 to a motor 1.
[0069] S20. Drive the motor 1 to accelerate to a preset speed;
[0070] S30. Perform an emergency stop operation on the motor 1, causing the motor 1 to generate energy feedback to the DC bus of the inverter 2, thereby causing the DC bus voltage to rise.
[0071] S40. By monitoring the DC bus voltage, when the DC bus voltage rises to a preset threshold, the braking unit 100 under test is triggered to work, and the feedback energy is consumed in the braking resistor 101 of the braking unit 100 under test.
[0072] S50. By adjusting the emergency stop time of the motor 1, the feedback energy consumed by the braking unit 100 under test is controlled, thereby realizing the testing of different braking power of the braking unit 100 under test.
[0073] In some possible embodiments, the preset threshold is determined by using analog circuitry to set the activation voltage of the braking unit.
[0074] In some possible embodiments, the emergency stop time is calculated and the motor is controlled using the following formula:
[0075] t=W / P
[0076] Where t is the emergency stop time of the motor, W is the kinetic energy of the motor at the preset speed, and P is the braking power of the braking unit under test, which is the braking power required to stop the motor.
[0077] In some possible embodiments, the motor is a motor with a power less than the rated braking power of the braking unit under test.
[0078] In some possible embodiments, the 1200KW braking power of the braking unit under test can be tested by using a 200KW motor.
[0079] For example, consider testing a 1200kW braking power using a 200kW motor: For a 200kW motor: Moment of inertia J = 50 kg.m^2, maximum speed n = 1450 rpm, the energy of the 200kW motor at its maximum speed: W = 1 / 2 * J * W^2 = 1 / 2 * J * (2*π*n / 60)^2, W = 577 (kJ). Therefore, the braking power required to stop from 1450 rpm is: P = W / t. If the braking power required is 1200kW, the deceleration time t = W / P = 577 / 1200 = 0.48 seconds; if the braking power required is 500kW, the deceleration time t = W / P = 577 / 500 = 1.15 seconds. As can be seen, based on this calculation, the stopping time can be adjusted to meet different braking power testing requirements.
[0080] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A method for testing a braking unit, comprising: Connect the braking unit to be tested to the DC bus of the frequency converter, and connect the frequency converter to the motor; Drive the motor to accelerate to a preset speed; An emergency stop operation is performed on the motor, causing the motor to generate energy feedback to the DC bus of the frequency converter, thereby causing the DC bus voltage to rise. By monitoring the DC bus voltage, when the DC bus voltage rises to a preset threshold, the braking unit is triggered to work, and the feedback energy is consumed in the braking resistor of the braking unit. By adjusting the emergency stop time of the motor, the feedback energy consumed by the braking unit can be controlled, thereby enabling the testing of different braking power of the braking unit under test.
2. The method according to claim 1, further comprising: The preset threshold is determined by setting the activation voltage of the braking unit using an analog circuit.
3. The method according to claim 1 or 2, further comprising: The emergency stop time is calculated and the motor is controlled using the following formula: t=W / P Where t is the emergency stop time of the motor, W is the kinetic energy of the motor at the preset speed, and P is the braking power of the braking unit under test, which is the braking power required to stop the motor.
4. The method according to any one of claims 1 to 3, further comprising: The motor is a motor with a power less than the rated braking power of the braking unit under test.
5. The method according to claim 4 can be used to test the 1200KW braking power of the braking unit under test by using a 200KW motor.
6. A braking unit testing system, characterized in that, include: An electric motor used to store kinetic energy; A frequency converter, connected to the motor, is used to drive the motor and receive energy fed back from the motor; One of the braking units under test is connected to the DC bus of the frequency converter and is used to consume energy when a trigger signal is received; A controller, the controller being configured to: The motor is driven to accelerate to a preset speed; an emergency stop operation is performed on the motor to rapidly decelerate it and feed the stored kinetic energy back to the DC bus of the frequency converter, thereby causing the DC bus voltage to rise; by monitoring the DC bus voltage, when the DC bus voltage reaches a preset threshold, a trigger signal is sent to the braking unit under test to activate it, thereby consuming the feedback energy in the braking resistor of the braking unit under test; By adjusting the emergency stop time of the motor, the feedback energy consumed by the braking unit under test can be controlled, thereby enabling the testing of different braking powers of the braking unit under test.
7. A braking unit testing system according to claim 6, characterized in that, The controller is configured to set the activation voltage of the braking unit under test through analog circuitry to determine the preset threshold.
8. The system according to claim 6 or 7, characterized in that, The motor is a motor with a power less than the rated braking power of the braking unit under test.
9. The system according to claim 8, characterized in that, The system can test the 1200KW braking power of the braking unit under test using a 200KW motor.