A steady-state noise detection system with cross-reference of dual motors coaxially connected

Abstract

The present invention discloses a steady-state noise detection system with a cross-reference of coaxial connection of two motors. Two identical motors are coaxially connected, and a three-phase AC power supply is supplied through a three-phase step-down transformer, and a DC bus is supplied through a three-phase PWM rectifier. The DC bus supplies power to a first inverter and a second inverter respectively, and the inverter supplies power to a first motor and a second motor respectively. The power supply mode of the inverter to the motor is controlled by a control module respectively, and a control method in the form of a double closed loop is adopted, namely, a speed loop and a current loop. The present invention uses two identical motors to operate under the same conditions to obtain the no-load vibration and electromagnetic noise of the two motors, and the comprehensive noise; then according to the change of the actual loading condition, the second motor is used as a reference, and the stator current value of the first motor and the noise of the fan chamber, stator housing, and the outer side of the bearing under different working conditions are collected, and the noise of the second motor in no-load operation is compared, and the data analysis is performed through a host computer.

Description

Technical Field

[0001] The present invention relates to a noise detection system, and in particular to the detection and analysis of various noises in a motor system. Background Art

[0002] Motors are a type of power equipment widely used in factories and mines. They are also the main source of noise that pollutes the environment. Noise not only affects people's living and working environment, causes harm to human health, but also reduces people's work efficiency. Motor noise control has always been a hot issue at present, but controlling noise first involves detecting noise. The noise of motor operation is mainly composed of three types of noise: electromagnetic noise, mechanical noise, and aerodynamic noise. Electromagnetic noise is mainly the noise radiated by the vibration of the stator; mechanical noise is mainly caused by the rotor and bearings; aerodynamic noise includes the fan, the rotating rotor, and the airflow noise formed when the airflow flows along the wind path. When the motor is running, these three types of noise are mixed together. At present, noise detection basically uses one motor, and the detection method is mainly based on national or industry-related standards, such as "GB1032-2008 Three-phase Asynchronous Motor Test Method", "GB / T21418-2008 Permanent Magnet Brushless Motor System General Technical Conditions", etc. As a manufacturer of motors and motor drivers, it is necessary to establish a compact and easy-to-operate noise detection platform and method. Summary of the invention

[0003] Based on the above problems, the present invention proposes a steady-state noise detection system with cross-reference of coaxially connected dual motors to collect, detect and analyze the electromagnetic noise, mechanical noise and aerodynamic noise of the motors.

[0004] The technical solution adopted is: a steady-state noise detection system with coaxial connection and cross-reference of two motors, wherein the first motor and the second motor are coaxially connected through a dynamometer, and the first motor and the second motor are respectively connected to a three-phase step-down transformer through a three-phase multi-throw circuit breaker for power supply; the three-phase step-down transformer is connected to a three-phase PWM rectifier through a three-phase multi-throw circuit breaker, and the three-phase PWM rectifier supplies power to a DC bus, and the DC bus is respectively connected to a first inverter and a second inverter; the first inverter is connected to the first motor through a three-phase multi-throw circuit breaker; the second inverter is connected to the second motor through a three-phase multi-throw circuit breaker; the first inverter is connected to a first control module; the second inverter is connected to a second control module; the first control module and the second control module are respectively connected to a host computer; a first noise sensor combination is fixed around the first motor; and a second noise sensor combination is fixed around the second motor.

[0005] The first motor and the second motor are three-phase asynchronous motors with the same technical parameters and models.

[0006] The first motor is connected to the first control module via a first encoder; the second motor is connected to the second control module via a second encoder.

[0007] The first noise sensor assembly is composed of the first noise sensor being fixed on the fan chamber, stator housing and outer side of the bearing of the first motor respectively; the second noise sensor assembly is composed of the second noise sensor being fixed on the fan chamber, stator housing and outer side of the bearing of the second motor respectively.

[0008] The first control module sets the voltage, current, speed and torque parameters of the first motor; the second control module sets the voltage, current, speed and torque parameters of the second motor.

[0009] The first noise sensor is respectively located 1 cm to 10 cm away from the fan chamber, the stator housing, and the outer side of the bearing of the first motor.

[0010] The second noise sensor is respectively located 1 cm to 10 cm away from the fan chamber, the stator housing, and the outer side of the bearing of the second motor.

[0011] A method for detecting steady-state noise with cross-reference of coaxial connection of two motors, the steps are as follows:

[0012] Step 1, check the power supply voltage, adjust the secondary voltage of the three-phase step-down transformer to 380V, check all switches, and they are all in the disconnected state; remove the end cover and fan of the first motor respectively, close the 2nd and 4th sides of the three-phase multi-throw circuit breaker, start the first motor, and when the rated speed is reached and the speed is stable, 3 to 5 seconds after stabilization, synchronously detect the first noise sensor of the fan room, stator housing, and outer side of the bearing of the first motor, collect data samples, the sample collection time period is 10 seconds, create a time and noise sequence backup, and create a file noise101; noise101 is the no-load vibration and electromagnetic noise of the first motor;

[0013] Step 2, using the same method as step 1, remove the end cover and fan of the second motor, disconnect switches 4 and 2, close switches 3 and 6, start the second motor, and when the rated speed is reached and the speed is stable, 3 to 5 seconds after stabilization, synchronously detect the second noise sensor of the fan room, stator housing, and bearing outside of the second motor, collect data, and back up the noise data noise201; noise201 is the no-load vibration and electromagnetic noise of the second motor; by running two identical motors under the same conditions, the difference in noise power levels is basically the same, and the second motor is used as a reference to obtain the no-load vibration and electromagnetic noise of the two motors;

[0014] Step 3, install the fan and end cover of the motor, detect the noise of the first motor in the same way as step 1, and detect the noise of the second motor in the same way as step 2, and establish noise data noise102 and noise202 respectively; noise102 is the comprehensive noise of the first motor when it is idling; noise202 is the comprehensive noise of the second motor when it is idling; by running two identical motors under the same conditions, the difference in noise power levels is basically the same, and the second motor is used as a reference to obtain the comprehensive noise.

[0015] Next, one of the motors is used for loading noise detection, and the other is used as a reference.

[0016] Step 4. First, disconnect all switches and check if the circuit is intact, then close switches 1 and 5, adjust the control mode of the first control module to a given rated speed, start the first motor, reach the rated speed and stabilize the speed, collect the three-phase current value of the first motor stator input 3 to 5 seconds after stabilization, collect the time period of 10 seconds, create the file NOI103, and synchronously detect the first noise group: that is, the first noise sensor of the fan room, stator housing, and the outside of the bearing, the sample collection time period is 10 seconds, create a time and noise sequence backup, and create the file file noise103; noise103 is the noise at three different positions when the first motor is unloaded, namely the fan room, stator housing, and the outside of the bearing; NOI103 is the stator winding current value when the first motor is unloaded; the stator current of the first motor and the noise at three different positions are collected as a reference for the subsequent motor loading;

[0017] Step 5. Adjust the control mode of the second control module so that the speed of the second motor is 70% of the rated speed, close switch 7, start the second motor, collect the three-phase current value of the stator input of the first motor, collect the time period of 10 seconds, create the file NOI104, and synchronously detect the first noise group, the first noise sensor of the fan room, the stator housing, and the outer side of the bearing; the sample collection time period is 10 seconds, create a time and noise sequence backup, and create the file file noise104; noise104 is the noise at three different positions, namely the fan room, the stator housing, and the outer side of the bearing when the first motor is loaded by 30%, and NOI104 is the stator winding current value when the first motor is loaded by 30% of the rated speed; the stator current value of the first motor and the noise collection under different working conditions are compared with the noise of the second motor when running at no load;

[0018] Step 6. Adjust the second control module again, the control mode is that the speed of the second motor is 30% of the rated speed, close switch 7, the second motor runs, collect the three-phase current value of the stator input of the first motor, the collection time period is 10 seconds, create the file NOI105, and synchronously detect the first noise group: the first noise sensor of the fan room, stator housing, and the outside of the bearing; the sample collection time period is 10 seconds, create a time and noise sequence backup, and create a file file noise105; noise105 is the noise of three different positions when the first motor is loaded with 70%, namely the fan room, stator housing, and the outside of the bearing; NOI105 is the stator winding current value when the first motor is loaded with 70% of the rated speed;

[0019] Step 7. The host computer performs data analysis.

[0020] The present invention connects two identical motors coaxially, and the three-phase AC power supply is powered by a three-phase step-down transformer, and the DC bus is powered by a three-phase PWM rectifier, and the DC bus is powered by a first inverter and a second inverter respectively, and the two inverters are powered by the first motor and the second motor respectively. The power supply mode of the two inverters to the two motors is controlled by the first control module and the second control module respectively, and a double closed-loop control method is adopted, namely, a speed loop and a current loop; if it is a servo drive, a position loop can be added, and the noise power level difference is basically the same when running under the same conditions. The second motor is used as a reference to obtain the no-load vibration and electromagnetic noise of the two motors, and the comprehensive noise; then according to the change of the actual loading situation, the stator current value of the first motor and the noise of the fan chamber, stator housing, and the outer side of the bearing under different working conditions are collected, and compared with the noise of the second motor when running at no load, and the data is analyzed by the host computer. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural block diagram of a dual-motor coaxially connected cross-reference steady-state noise detection system of the present invention;

[0022] Figure 2 It is a schematic diagram of the position structure of the first noise group in a steady-state noise detection system with cross-reference of dual motors coaxially connected according to the present invention;

[0023] Figure 3 It is a schematic diagram of the position structure of the second noise group in a steady-state noise detection system with coaxial connection and cross-reference of dual motors of the present invention. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and by way of examples. The following examples are intended to explain the present invention but the present invention is not limited to the following examples.

[0025] See also Figures 1 to 3As shown, a steady-state noise detection system with a cross-reference of coaxial connection of two motors is provided. The first motor 1 and the second motor 3 are coaxially connected through a dynamometer. The first motor 1 and the second motor 3 are three-phase asynchronous motors with the same technical parameters and models. The first motor 1 and the second motor 3 are respectively connected to a three-phase step-down transformer 2 through a three-phase multi-throw circuit breaker for power supply; the three-phase step-down transformer 2 is connected to a three-phase PWM rectifier 9 through a three-phase multi-throw circuit breaker, and the three-phase PWM rectifier 9 supplies power to a DC bus, which is respectively connected to a first inverter 8 and a second inverter 6; the first inverter 8 is connected to the first motor 1 through a three-phase multi-throw circuit breaker; the second inverter 6 is connected to the second motor 3 through a three-phase multi-throw circuit breaker; the first inverter 8 is connected to a first control module 7; the second inverter 6 is connected to a second control module 5; the first control module 7 and the second control module 5 are respectively connected to an upper computer 4; a first noise sensor assembly 13 is fixed around the first motor 1; and a second noise sensor assembly 12 is fixed around the second motor 3. The first control module 7 sets the voltage, current, speed and torque parameters of the first motor 1 ; the second control module 5 sets the voltage, current, speed and torque parameters of the second motor 3 .

[0026] The first motor 1 is connected to the first control module 7 via a first encoder 10 ; the second motor 3 is connected to the second control module 5 via a second encoder 11 .

[0027] The first noise sensor assembly is to fix the first noise sensor 14 in the fan room, stator housing and bearing outer side of the first motor 1 respectively; the first noise sensor is 1 cm to 10 cm away from the fan room, stator housing and bearing outer side of the first motor respectively.

[0028] The second noise sensor assembly is to fix the second noise sensor 15 in the fan room, stator housing and bearing outer side of the second motor respectively; the second noise sensor is 1cm-10cm away from the fan room, stator housing and bearing outer side of the second motor respectively.

[0029] A method for detecting steady-state noise with cross-reference of coaxial connection of two motors, the steps are as follows:

[0030] Step 1, check the power supply voltage, adjust the secondary voltage of the three-phase step-down transformer to 380V, check all switches, and they are all in the disconnected state; remove the end cover and fan of the first motor respectively, close the 2nd and 4th sides of the three-phase multi-throw circuit breaker, start the first motor, and when the rated speed is reached and the speed is stable, 3 to 5 seconds after stabilization, synchronously detect the first noise sensor of the fan room, stator housing, and outer side of the bearing of the first motor, collect data samples, the sample collection time period is 10 seconds, create a time and noise sequence backup, and create a file noise101; noise101 is the no-load vibration and electromagnetic noise of the first motor;

[0031] Step 2, using the same method as step 1, remove the end cover and fan of the second motor, disconnect switches 4 and 2, close switches 3 and 6, start the second motor, and when the rated speed is reached and the speed is stable, 3 to 5 seconds after stabilization, synchronously detect the second noise sensor of the fan room, stator housing, and bearing outside of the second motor, collect data, and back up the noise data noise201; noise201 is the no-load vibration and electromagnetic noise of the second motor; by running two identical motors under the same conditions, the difference in noise power levels is basically the same, and the second motor is used as a reference to obtain the no-load vibration and electromagnetic noise of the two motors;

[0032] Step 3, install the fan and end cover of the motor, detect the noise of the first motor in the same way as step 1, and detect the noise of the second motor in the same way as step 2, and establish noise data noise102 and noise202 respectively; noise102 is the comprehensive noise of the first motor when it is idling; noise202 is the comprehensive noise of the second motor when it is idling; by running two identical motors under the same conditions, the difference in noise power levels is basically the same, and the second motor is used as a reference to obtain the comprehensive noise.

[0033] Next, one of the motors is used for loading noise detection, and the other is used as a reference.

[0034] Step 4. First, disconnect all switches and check if the circuit is intact, then close switches 1 and 5, adjust the control mode of the first control module to a given rated speed, start the first motor, reach the rated speed and stabilize the speed, collect the three-phase current value of the first motor stator input 3 to 5 seconds after stabilization, collect the time period of 10 seconds, create the file NOI103, and synchronously detect the first noise group: that is, the first noise sensor of the fan room, stator housing, and the outside of the bearing, the sample collection time period is 10 seconds, create a time and noise sequence backup, and create the file file noise103; noise103 is the noise at three different positions when the first motor is unloaded, namely the fan room, stator housing, and the outside of the bearing; NOI103 is the stator winding current value when the first motor is unloaded; the stator current of the first motor and the noise at three different positions are collected as a reference for the subsequent motor loading;

[0035] Step 5. Adjust the control mode of the second control module so that the speed of the second motor is 70% of the rated speed, close switch 7, start the second motor, collect the three-phase current value of the stator input of the first motor, collect the time period of 10 seconds, create the file NOI104, and synchronously detect the first noise group, the first noise sensor of the fan room, the stator housing, and the outer side of the bearing; the sample collection time period is 10 seconds, create a time and noise sequence backup, and create the file file noise104; noise104 is the noise at three different positions, namely the fan room, the stator housing, and the outer side of the bearing when the first motor is loaded by 30%, and NOI104 is the stator winding current value when the first motor is loaded by 30% of the rated speed; the stator current value of the first motor and the noise collection under different working conditions are compared with the noise of the second motor when running at no load;

[0036] Step 6. Adjust the second control module again, the control mode is that the speed of the second motor is 30% of the rated speed, close switch 7, the second motor runs, collect the three-phase current value of the stator input of the first motor, the collection time period is 10 seconds, create the file NOI105, and synchronously detect the first noise group: the first noise sensor of the fan room, stator housing, and the outside of the bearing; the sample collection time period is 10 seconds, create a time and noise sequence backup, and create a file file noise105; noise105 is the noise of three different positions when the first motor is loaded with 70%, namely the fan room, stator housing, and the outside of the bearing; NOI105 is the stator winding current value when the first motor is loaded with 70% of the rated speed;

[0037] Step 7. The host computer performs data analysis.

Claims

1. A dual-motor coaxially connected cross-reference steady-state noise detection system, characterized by: The first motor and the second motor are coaxially connected through a dynamometer, and the first motor and the second motor are respectively connected to a three-phase step-down transformer through a three-phase multi-throw circuit breaker for power supply; the three-phase step-down transformer is connected to a three-phase PWM rectifier through a three-phase multi-throw circuit breaker, and the three-phase PWM rectifier supplies power to a DC bus, and the DC bus is respectively connected to a first inverter and a second inverter; the first inverter is connected to the first motor through a three-phase multi-throw circuit breaker; the second inverter is connected to the second motor through a three-phase multi-throw circuit breaker; the first inverter is connected to a first control module; the second inverter is connected to a second control module; the first control module and the second control module are respectively connected to a host computer; a first noise sensor combination is fixed around the first motor; a second noise sensor combination is fixed around the second motor; The first motor and the second motor are three-phase asynchronous motors with the same technical parameters and models; The first noise sensor assembly is respectively fixed on the fan chamber, stator housing and outer side of the bearing of the first motor; the second noise sensor assembly is respectively fixed on the fan chamber, stator housing and outer side of the bearing of the second motor.

2. A dual-motor coaxially connected cross-reference steady-state noise detection system according to claim 1, characterized in that The first motor is connected to the first control module via a first encoder; the second motor is connected to the second control module via a second encoder.

3. A dual-motor coaxially connected cross-reference steady-state noise detection system according to claim 1, characterized in that The input part of the first control module sets the voltage, current, speed and torque parameters of the first motor; the input part of the second control module sets the voltage, current, speed and torque parameters of the second motor.

4. A dual-motor coaxially connected cross-reference steady-state noise detection system according to claim 1, characterized in that The first noise sensor is respectively located 1 cm to 10 cm away from the fan chamber, the stator housing, and the outer side of the bearing of the first motor.

5. A dual-motor coaxially connected cross-reference steady-state noise detection system according to claim 1, characterized in that The second noise sensor is respectively located 1 cm to 10 cm away from the fan chamber, the stator housing, and the outer side of the bearing of the second motor.

6. A method for detecting steady-state noise with cross-reference of dual motor coaxial connection, characterized in that: Here are the steps: Step 1, check the power supply voltage, adjust the secondary voltage of the three-phase step-down transformer to 380V, check all switches, and they are all in the disconnected state; remove the end cover and fan of the first motor respectively, close the 2nd and 4th sides of the three-phase multi-throw circuit breaker, start the first motor, and when the rated speed is reached and the speed is stable, 3 to 5 seconds after stabilization, synchronously detect the first noise sensor of the fan room, stator housing, and outer side of the bearing of the first motor, collect data samples, the sample collection time period is 10 seconds, create a time and noise sequence backup, and create a file file noise101; noise101 is the no-load vibration and electromagnetic noise of the first motor; Step 2, using the same method as step 1, remove the end cover and fan of the second motor, disconnect switches 4 and 2, close switches 3 and 6, start the second motor, and when the rated speed is reached and the speed is stable, 3 to 5 seconds after stabilization, synchronously detect the second noise sensor of the fan room, stator housing, and bearing outside of the second motor, collect data, and back up the noise data noise201; noise201 is the no-load vibration and electromagnetic noise of the second motor; Step 3, install the fan and end cover of the motor, detect the noise of the first motor in the same way as step 1, and detect the noise of the second motor in the same way as step 2, and establish noise data noise102 and noise202 respectively; noise102 is the comprehensive noise of the first motor when it is idling; noise202 is the comprehensive noise of the second motor when it is idling; Next, one of the motors is used for loading noise detection, and the other is used as a reference. Step 4. First, disconnect all switches and check if the circuit is intact, then close switches 1 and 5, adjust the control mode of the first control module to a given rated speed, start the first motor, reach the rated speed and stabilize the speed, collect the three-phase current value of the first motor stator input 3 to 5 seconds after stabilization, the collection time period is 10 seconds, create the file NOI103, and synchronously detect the first noise group: that is, the first noise sensor of the fan room, stator housing, and the outside of the bearing, the sample collection time period is 10 seconds, create a time and noise sequence backup, and create the file file noise103; noise103 is the noise of three different positions when the first motor is unloaded, namely the fan room, stator housing, and the outside of the bearing; NOI103 is the stator winding current value when the first motor is unloaded; Step 5. Close switch 7, adjust the second control module, adjust the speed of the second motor to 70% of the rated speed, close switch 7, start the second motor, collect the three-phase current value of the stator input of the first motor, collect the time period of 10 seconds, create the file NOI104, and synchronously detect the first noise group, the first noise sensor of the fan room, the stator housing, and the outer side of the bearing; the sample collection time period is 10 seconds, create a time and noise sequence backup, and create a file file noise104; noise104 is the noise at three different positions, namely the fan room, the stator housing, and the outer side of the bearing when the first motor is loaded by 30%, and NOI104 is the stator winding current value when the first motor is loaded with 30% of the rated speed; Step 6. Adjust the second control module again, adjust the speed of the second motor to 30% of the rated speed, close switch 7, the second motor runs, collect the three-phase current value of the stator input of the first motor, collect the time period of 10 seconds, create the file NOI105, and synchronously detect the first noise group: the first noise sensor of the fan room, stator housing, and the outer side of the bearing; the sample collection time period is 10 seconds, create a time and noise sequence backup, and create the file file noise105; noise105 is the noise of three different positions when the first motor is loaded with 70%, namely the fan room, stator housing, and the outer side of the bearing; NOI105 is the stator winding current value when the first motor is loaded with 70% of the rated speed; Step 7. Data analysis.

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