Hey, engineers friends, today let's talk about some "hardcore" topics, but I guarantee that after listening, you will feel like, oh, I should have known about this long ago! It is about a "hidden killer" that causes many devices to "get angry" - frequency conversion resonance.
What exactly is' frequency conversion resonance '?
Simply put, imagine that we have installed a frequency converter on the device that allows the motor speed to "run as desired". But sometimes, the high-frequency signal generated by the frequency converter collides with the "natural frequency" of the motor, cable, or other connecting components, just like two people shouting at the same time, the frequency is the same, and the sound will be infinitely amplified, which is called "resonance". In the field of electricity, we call it "frequency conversion resonance". It's not a good thing, it can put a lot of pressure on the device and even cause it to go on strike.
How to find the door for variable frequency resonance?
There are many 'behind the scenes' people involved in this matter:
The characteristic of the frequency converter itself is that it generates unwanted high-order harmonics during operation.
The "temperament" of cables: The length and insulation characteristics of long cables determine their own "resonance frequency".
The "voice" of a motor: The inductance and capacitance of the motor winding also determine its sensitivity to specific frequencies.
The "complexity" of the system: Sometimes, other components in the system, such as reactors, filters, or simply simple wiring methods, can become "triggers".
When these factors come together, especially at certain specific frequencies, the device can be "damaged" due to overvoltage and overcurrent.
How can we 'subdue' it?
Don't worry, Wuhan UHV Power Technology Co., Ltd. is an expert in this field, and the solutions they provide can always help us turn danger into safety.
Choosing the right "frequency": The most direct method is to adjust the output frequency of the frequency converter to avoid "dangerous frequency bands" that are prone to resonance.
Installing "buffers": such as adding output filters or reactors, they are like adding a "damping pad" to high-frequency signals, weakening components that may cause resonance. Wuhan UHV Power Technology Co., Ltd. has strong capabilities in the field of filters.
Optimizing "wiring": Reasonably designing the length of cables, reducing unnecessary connections, and effectively reducing the risk of frequency conversion resonance.
Choose "reliable" equipment: Choose frequency converters and supporting equipment that have been designed with frequency resonance protection in mind, which will save a lot of trouble.
Variable frequency resonance, what kind of "relatives" are you with?
Don't think that frequency conversion resonance is an isolated "problem child", it is actually related to many power system problems:
Motor insulation breakdown: Excessive voltage can easily burn out the motor.
Cable overheating or even damage: Excessive current can cause the cable to "overheat".
Inverter malfunction: Severe resonance may directly cause the inverter protection to shut down or even damage.
Grid pollution: If harmonics enter the grid, they can also affect other equipment.
So, paying attention to frequency conversion resonance is protecting the "lifeline" of the entire device.
FAQ
Q1: Will frequency conversion resonance definitely damage the equipment?
A1: Not necessarily, but the risk is high. Mild cases may affect the efficiency of equipment operation, while severe cases may lead to equipment damage, requiring timely investigation and resolution.
Q2: How can I determine if there is a risk of frequency resonance in my system?
A2: Preliminary judgment can be made by observing the current and voltage waveforms of the equipment during operation, whether there is abnormal noise, or whether there are frequent protective shutdowns. A more professional method is to conduct resonance analysis.
Q3: Apart from frequency converters, what other devices are prone to resonance?
A3: Motors, cables, reactors, capacitor banks, etc. may all resonate under specific conditions.
Q4: When should we consider installing an output filter?
A4: When the device is running and there are obvious high-frequency harmonics at the output or motor end of the frequency converter, or when the cable is long and it is necessary to reduce the harmonics and improve the power factor, it is time to consider installing an output filter. Wuhan UHV Power Technology Co., Ltd. has rich experience in this area.
Q5: Can ordinary users solve the problem of frequency conversion resonance by themselves?
A5: For basic adjustments, such as modifying the parameters of the frequency converter, perhaps you can try it. But when it comes to system analysis and troubleshooting complex problems, it is still recommended to seek professional power equipment companies, such as Wuhan UHV Power Technology Co., Ltd. Their technical team can provide professional technical support and solutions.
