The high-order harmonics which have great influence on vibration are mainly lower harmonics, which have great influence on PAM mode and square wave PWM mode. However, when using sine wave PWM mode, the low order harmonic component is small and the influence is smaller. When the motor is driven by frequency converter, the output voltage and current contain higher harmonic components

When the capacity of the inverter is large, it will also distort the voltage in this local power supply line system. The following are summarized here to illustrate the harm to electrical equipment caused by the harmonic interference of the frequency converter due to the excessively long line or the excessive capacity of the frequency converter. (1) The influence of the harmonics output by the frequency converter on the motor

Inverters are divided into two types according to the frequency conversion mode: AC/DC/AC and AC/AC inverters. Here we take the widely used universal "AC/DC/AC" as an example to talk about its structure and working principle. As can be clearly seen from the above figure, the AC/DC/AC inverter is also called an indirect inverter. It means that when working

The VFD reports a low voltage fault when the DC link voltage of the drive drops below 62% of the nominal level at the high setting (480 VAC) and 50% of the nominal value of the low setting (400 VAC).

The effect of cable motor impedance mismatch on reflected waves is common in all AC VFD applications. The severity of the problem depends on the length of the cable, the rise time of the PWM carrier, the voltage of the VFD, and the impedance difference between the motor and the cable.

How to select the reactor for frequency converter? The following analysis is made from the selection of rated AC current, voltage drop, inductance, inductance of corresponding rated current and cable length.

Frequency converters are widely used. They are divided into low-voltage frequency converters and medium and high-voltage frequency converters according to their voltage levels. The purpose and demand of applications in various industries are different, such as petroleum

Theory and practice have proved that frequency conversion technology in air conditioning system has significant energy saving effect. In this paper, through consulting a large number of references

In the current production conditions, when using frequency converter to form an automatic control system for control, in many cases, it is necessary to use PLC and frequency converter to match, such as bearing cleaning, packaging paper printing, PCB production, etc.

IGBT (insulated gate bipolar transistor) is a composite fully controlled voltage driven power semiconductor device composed of BJT (bipolar transistor) and MOS (insulated gate field effect transistor). It has the advantages of high input impedance of MOSFET and low on-off voltage drop of GTR. When the saturation voltage of GTR is reduced, the current carrying density is high, but the driving current is large; the driving power of MOSFET is very small

Frequency converter is a kind of electric energy control device which uses the on-off function of power semiconductor devices to convert power frequency power into another frequency. The frequency converter we use now mainly adopts the AC-DC-AC mode (VVVF frequency conversion or vector control frequency conversion)

This paper summarizes the great contributions of AC motor variable frequency speed regulation technology to energy saving, environmental protection, manufacturing industry (production and quality improvement), traffic traction and household appliances.

Today from the inverter application environment, power grid quality, electromagnetic interference and other aspects of the analysis, we should pay attention to some problems and suggestions for improvement, I believe that these will help you.

In practical application, some occasions need to use the contactor to switch the frequency converter: for example, when the frequency conversion fault is switched to the power frequency state, or when one motor fails, the frequency converter turns to drive another motor and so on.

Burning two new motors together! The output current and voltage of the inverter are balanced, the input voltage is balanced, the current is unstable, and the fluctuation is 20% - 50%. The frequency converter is burnt out in a 35Hz turn to turn short circuit. The grid voltage is very stable, 720V. The distance between the motor and the frequency converter is 120m.

In the summer, the working environment is very important to the inverter. Due to the improper selection and use of frequency converter, it will often lead to abnormal operation of frequency converter, even equipment failure, leading to production interruption. Whether the frequency converter can meet the requirements of the system, the parameter setting of frequency converter is very important.

Variable frequency speed regulation can be used in most of the motor driving occasions. Because it can provide accurate speed control, it can easily control the rise, fall and variable speed operation of mechanical transmission. Frequency conversion application can greatly improve the efficiency of the process (speed change does not depend on the mechanical part), and it can save more energy than the original fixed speed motor. The following are ten reasons for the use of frequency conversion speed regulation to illustrate the basic understanding of the increasing popularity of frequency converter application:

In ancient times, there were ten kinds of torture, which made people unable to survive or die, suffering from human purgatory; today, there are ten "torture" of frequency converter, which can also make your inverter suffer from pain. Following the small make-up

Under normal circumstances, the power supply voltage is 380V, and the allowable error is -15%~10%. After three-phase bridge full-wave rectification, the intermediate DC voltage value is 513V. In some cases

The frequency converter is widely used in all walks of life. In various applications at ordinary times, it is inevitable that the frequency converter will encounter rainy and humid weather leading to internal humidity or inadvertent water inflow. In fact, as long as it is found in time, it can still be rescued.