Frequency conversion motor & # 8203; Today's lesson is hungry a little common sense on the frequency conversion motor, frequency conversion power, what is frequency conversion power, this have what use? He will be affected by which parameters? An overview, frequency conversion power with variable frequency speed regulation technology, the development of new energy grid inverter technology, power electronics engineers gradually found that measurement, measurement, control, maintenance process faced by the main parameter & ndash; —Power has been a qualitative change. Let's call this kind of power frequency conversion power, in addition to the frequency converter and inverter output power, frequency conversion power refers to all with the intention of transmission power, wide frequency coverage scale or the frequency components is messy. Second, the frequency conversion power difficulty in speaking of variable frequency power, the most easy to relate to people is frequency conversion air conditioning, inverter, variable frequency constant pressure water supply, etc. This kind of frequency conversion equipment of frequency conversion, is refers to the fundamental wave frequency variable. Because of this, many people think, variable frequency power is the wide frequency scale. In fact, frequency conversion power not only occurred in the equipment, and even the equipment of frequency conversion power, fundamental frequency change is only intention, in terms of frequency conversion power itself characteristic, change is not only a frequency. Power frequency electric quantity has significant rules, it can express in brief sine or cosine function, and because the frequency of a single fixed, measurement or record is very brief and convenient. According to the principle of Fourier transform, non sinusoidal periodic signal can be decomposed into different amplitude, frequency and phase of a linear combination of the sine signals, and are the sine wave frequency signal frequency (Fundamental wave frequency)Integer times. In this way, we can use series of amplitude, frequency, phase quantization values to represent arbitrary mixed and disorderly periodic signal. From the perspective of signal processing, a non sinusoidal periodic power willfully intact, now the main processing methods are based on Fourier transform. Therefore, start from the perspective of measurement instruments, the non-sinusoidal power all classified as frequency conversion power. Frequency conversion power in English is: the Variable Frequency Electrica, abbreviated VFE. “Measurement with frequency conversion power transmitter & throughout; For frequency conversion power define as follows: frequency conversion power is used for the transmission of power, and one of the following conditions are satisfied communication power. 1. Signal spectrum includes only a kind of frequency components, but is not limited to power frequency communication frequency electrical signal. 2. Signal spectrum includes two or more frequency components of the electrical signals. Frequency conversion power including voltage, current and voltage current of active power, reactive power, apparent power, active power, reactive power, etc. 1 3, frequency conversion power characteristics. Frequency conversion power includes rich information, has wide frequency band; 2. Frequency conversion power used to pass the electric energy, high voltage, large current; 3. Frequency conversion power usually occurred directly by the frequency converter, rectifier, switch power supply or cause; 4. Frequency conversion power measurement behavior often end in clutter electromagnetic environment. Four, frequency conversion power measurement of frequency conversion power is not only the change of frequency, frequency conversion power measurement and measurement, is a new subject, frequency conversion power of electric parameter measurement instrument is put forward new requirements. The theory and practice prove that: 1. Frequency 50 hz, the effective value is 100 v of PWM wave, choose different appearance, the measurement results can in 100 ~ 1000 v and even wider scale within the change! 2. 5% frequency measurement errors, the effects of sinusoidal power in 0. Within 01%, and the influence on frequency conversion power could reach 100%. 3. Of phase resolution power factor, no longer have a clear physical meaning! Now commonly used frequency conversion power measurement instrument is mainly all kinds of frequency conversion power analysis instrument, the high precision power analysis instrument, wide-band power analysis instrument, power quality analysis instrument, the harmonic detector and so on.
