Generally speaking, the inverter will inevitably present some problems during operation, such as oscillation and noise, which are common problems in VFD operations. So, what causes oscillation and noise in VFDs? What is the solution to these problems? The following are the causes and how to deal with VFD oscillation and noise.
The reason for the oscillation and noise is that during VFD operation, the magnetic field generated by the higher harmonics in the output waveform produces electromagnetic force for many mechanical parts, and the frequency of the driving force is always close to or coincides with the natural frequency of some mechanical parts, resulting in resonance.
The higher harmonics that have a greater influence on the oscillation are mainly the lower harmonic components, which are more influential in the PAM form and the square wave PWM form. However, when the sine wave PWM method is adopted, the weight of the lower harmonic is small, and the influence is smaller. When a VFD is used to drive a motor, the output voltage and current contain higher harmonic components, and the higher harmonic magnetic flux of the air gap increases, resulting in an increase in noise. The following features are given by the electromagnetic instrument international network: because the weight of the lower harmonics in the VFD resonates with the natural mechanical frequency of the rotor, the noise in the vicinity of the natural frequency of the rotor increases. The weight of the higher harmonics in the VFD output resonates with the bearing frame of the core housing. , and the noise of the corresponding natural frequencies of these parts is added. The noise, especially the screeching generated by the VFD drive motor, is related to the switching frequency of the PWM operation, especially in the low frequency range. When a VFD is used for speed regulation, noise and oscillations are generated, which are caused by the weight of the higher harmonics in the VFD output waveform. With the change of operating frequency, the fundamental weight and the weight of higher harmonics change in a large range, which may resonate with all parts of the motor.
Oscillation and Noise HandlingIn order to reduce or eliminate oscillation, a communication reactor can be connected to the VFD output to absorb the weight of the higher harmonic current in the VFD output current.
When using a PAM or square wave PWM VFD, a sine wave PWM VFD can be used to reduce the ripple torque. In order to prevent the oscillation of the mechanical system consisting of the motor and the load, the entire system must not resonate with the electromagnetic force generated by the motor. In general, the following method is used to suppress and reduce noise: the communication reactor is connected to the output side of the VFD. If there is an electromagnetic torque margin, the U/f can be set even smaller. If a special motor is used, if the noise level at lower frequencies is severe, the resonance with the natural frequency of the shaft system (including the load) should be checked.
|
More on that
|
The reason for adding a frequency converter to the crane control system - Senland
Prior to the introduction of frequency converters, overhead crane operators operated the cranes using contactor-based controls. For low-cycle cranes, the system is equipped with a single or two-speed motor. For cranes with higher load cycles, they use so-called wound rotor motors.
...
|
|
Industrial control circuit board capacitor damage fault characteristics and maintenance - Senlan
Capacitor damage is the highest problem in electronic devices, especially electrolytic capacitors.
Capacitor damage is manifested in: 1. Capacity becomes smaller, 2. Capacity is completely lost, 3. Leakage, 4. Short circuit.
Electricity...
|
|
At the physical level, the stable operation of the inverter is guaranteed-Senlan inverter
For the most popular electrical control equipment inverter (Variable-frequency Drive, VFD), as a precision electronic industrial control equipment, in order to run smoothly for a long time, we, as professional and technical personnel, need to be on the VFD device or before the operation.
|
|
Measures to prevent overvoltage of inverter - Sunland inverter
Depending on the cause of overvoltage, the countermeasures adopted are different. Regarding the overvoltage phenomenon that occurs in the parking process, if there is no special requirement for the parking time or direction, then the extension inverter deceleration time or free parking method can be selected to solve it. The so-called free parking ...
|
|
Senlan inverter external detection and judgment
1. The power-on trip or the main power terminal part of the inverter shows a spark.
Detection method and discrimination: disconnect the power line, check whether the input terminal of the inverter is short-circuited, and check whether the DC side terminals P and N of the central circuit of the inverter are short-circuited. It may be due to a damaged rectifier or a central ...
|
|
Hope Sunland inverter EMC rules
When various factory equipment uses frequency conversion speed regulation, harmonic disturbances will be generated on the power supply side and motor side of the inverter (VFD), which will cause electromagnetic disturbance to the power supply network and other electrical equipment near the VFD. In addition, in order to ensure the long-term reliable operation of the VFD, the wiring of the VFD is very important.
...
|
|
Senlan SV1000 servo drive wearing parts replacement
The wearing parts of the driver mainly include electrolytic capacitors for filtering and cooling fans, and their service life is closely related to the environment and maintenance of the operation.
Depending on the operating moment, the user can determine whether a wear part needs to be replaced.
Cooling ...
|
|
Sunland inverter overcurrent fault maintenance method
When the inverter current is too large, exceeding the limit value of the inverter, the maintenance circuit will produce action, so that the inverter trips and stops, and the phenomenon of repairing such inverter can be divided into energized ...
|
|
Misunderstandings and solutions to the disadvantages of inverter application - Sunland inverter
Myth: The inverter selection only needs to consider the load power
When purchasing a frequency converter, many users usually only match the capacity of the frequency converter based on the power of the drive motor. In fact, the load driven by the motor is different, and the requirements for the inverter are also different.
...
|
|
Damage to the inverter power module of the inverter - Senland
1. Discrimination
The inverter power module mainly includes IGBT, IPM, etc., check whether the appearance has exploded, and whether there are ablation marks between the terminal and the connected printed board. Use a multimeter to check whether C-E, G-C, G-E have been passed, or use a multimeter to measure whether the resistance of P to U, V, W and N to U, V, W is inadequate.
|
|
Inverter remote control wiring method - Senlan
1. Connect X (switching input) drive terminal to control the inverter start-stop/forward and reverse rotation;
2. Connect to the AI (analog input) terminal to control the frequency of the inverter (perhaps made into PID closed-loop control active conditioning frequency)
3. Other DO (switching output) is used for transmission ...
|
|
Common problems in the use of inverter - Sunland inverter
1. Please explain the maintenance function of the inverter?
(1) After detecting the abnormal situation, the correction action will be carried out automatically, such as overcurrent loss rate prevention, regeneration overvoltage stall prevention.
(2) After detecting the abnormality, the PWM control signal of the power semiconductor device is closed, so that the motor can park automatically. As...
|
|
How to expand the application range of inverter - Sunland inverter
In the electrical profession, the use and development of energy-saving frequency conversion is very good, which has promoted the electrical profession to reach the pinnacle of science and technology again. Frequency converter (VFD) has a very good development shape in China, but it still has to withstand various tests. As long as you give full play to your professional advantages, you can gain a firm foothold in this society. VFD ...
|
|
The connection method of three-phase isolation transformer - Senland
The three-phase barrier transformer adopts a three-phase double-winding structure, which has the characteristics of lightning protection and anti-disturbance. Each winding on the primary and secondary sides is divided into two coils, which are wound from two layers of metal foil insulated from each other. So there is capacitance C (capacitance barrier transformer) between the two coils. Then, being able to ...
|
|
Sunland's measures to reduce inverter failure
According to the test, the service life of the inverter is halved for every 10°C increase in the operating ambient temperature. For this reason, in daily use, a reasonable maintenance cycle and guidelines should be formulated according to the actual operating environment and load characteristics of the inverter.
|
|
Methods to reduce the maintenance cost of inverter - Senlan inverter
Frequency converter is a widely used equipment in modern factories. This is a very expensive new type of equipment, and the maintenance price of the inverter is also very expensive, so in the process of using the inverter, we should pay attention to the use of the inverter.
Thing...
|
|
Motor encoder and rotor pole phase zero alignment repair - Sunland
1. Phase alignment method of incremental encoder
The alignment between the phase of the UVW electronic transmutation signal and the phase of the rotor pole, or the phase of the TV spot, of the incremental encoder with the signal exchange is as follows:
1) Use a DC power supply to pass the UV winding of the motor to less than the amount of ...
|
|
Introduction to the speed regulation mode of inverter motor - Senlan
1. Mechanical speed regulation form
There are three methods of mechanical speed regulation: electromagnetic clutch, hydraulic coupling, and viscous clutch. Among them, the hydraulic coupling device is widely used, that is, a hydraulic coupling device is connected in series between the motor and the load, and the concave and convex liquid level is used to adjust the hydraulic coupling between the motor and the load.
|
|
According to the load characteristics, choose the inverter - Senland
The types of production machinery are complex, the functional and process requirements are different, and the torque characteristics are also different, therefore, before the application of the inverter, the first thing is to understand the nature of the load carried by the motor, that is, the load characteristics, and then select the inverter and the motor. There are three types of loads: ...
|
|
Inverter maintenance and cleaning inspection method - Senlan inverter
There are many special faults, which come and go, looming, making it impossible to judge and deal with. At this time, you can clean the circuit board with water or alcohol, and brush off the dust and rust on the circuit board with a soft brush, especially pay attention to the solder joints are dense, and the circuit near the 0 volt copper layer is also ...
|
|
Contact
working hours
