Variable frequency drive (VFD) is a power control equipment that uses frequency conversion technology and microelectronics technology to control AC motor by changing the working power frequency of motor. It is also one of the essential equipment in various industrial and commercial occasions today!
In power quality assessment, frequency converters are typical harmonic source loads. Different brands of frequency converters not only produce different harmonic content, but also have different effects on power grid pollution and other electrical equipment. The operation of generalized up converter will cause fault problems to the system or other equipment, but do you know, The breeding of harmonics will also cause faults to the frequency converter!
The burning out of the circuit board of the frequency converter is a typical harmful phenomenon caused by harmonics. Here, harmonics refer to the background harmonics (also known as harmonic voltage). The background harmonics are a special electric energy value, which can directly affect the control system, resulting in equipment failure. Except for the burning out of the circuit board, in many control systems: PLC code jumping, short circuit between motor gates Production line equipment malfunction and so on are its “masterpiece”!
The behavior inertia of many power workers is to solve the problem when problems arise. The ideas for controlling background harmonics with high income Z after small compilation are as follows: 1. Install the background harmonic filter (lbbhf) independently developed by lingbu (Beijing) power quality equipment Co., Ltd., which can eliminate the harm of external background harmonic interference, It is necessary to carry out harmonic suppression, reduction and isolation protection for the power supply of the disturbed equipment or production line, and the external background harmonic is different from the harmonic generated by the internal equipment of the system, reflecting the characteristics of small harmonic current and high harmonic voltage, It is difficult to achieve better control effect by using conventional active or passive filters with harmonic current as the control target, and the cost is relatively low; 2. For enterprises with relatively sufficient budget investment cost, they can either directly replace the pressure transformation point for treatment or effectively manage it;