Performance of the frequency converter full understanding

The performance of the inverter is called function, these indicators can be through a variety of measuring instruments and tools in a relatively short period of time measurement, such indicators are factory inspection required by IEC standard and gb quality indicators. The user to select a few key indicators can know the quality of high and low frequency converter, rather than just looking is imported or domestic, it is expensive or cheap. Here are several key performance indicators of frequency converter. ( 1) At zero. 5 hz can output the starting torque of much more excellent inverter in 0. 5 hz can output 200% high starting torque, More than 30 kw under 22 kw, and can output 180% of the starting torque) 。 Has the performance of the inverter, can achieve smooth deceleration short time according to load requirements, rapid response rapidly varied load, the timely detection of renewable power. ( 2) Frequency index. Frequency indexes including the frequency range of frequency converter, frequency stability precision and frequency resolution. Frequency range with the highest frequency inverter output fmax fmin mark and the lowest frequency, all kinds of different frequency range of frequency converter. Usually, the lowest operating frequency is about 0. 1 ~ 1 hz, the highest working frequency is about 200 ~ 500 hz. Precision of frequency stability is also called frequency precision, refers to the frequency under the condition of given value remains the same, when the temperature, load, voltage fluctuation or working long hours, the actual output frequency of frequency converter with a given frequency between the ratio of the maximum error and maximum working frequency ( Expressed in percentage) 。 For example, a user given the highest working frequency fmax = 120 hz, the frequency accuracy of 0. Maximum error is 01%, the: & Delta; fmax = 0。 0001× 120Hz＝0. 012 hz, usually by the frequency of the digital quantity to timing accuracy than analog to high precision timing frequency of an order of magnitude, the former usually can achieve & plusmn; 0. 01% ( - 10～＋50℃） , the latter can usually achieve & plusmn; 0. 5% [( 25± 10) ℃). Frequency resolution refers to the smallest change of the output frequency, the minimum difference between every two adjacent block frequency. For example, when the working frequency fx = 25 hz, if the inverter frequency resolution of 0. 01 hz, the minimum frequency on a block is: fn′ = ( 25 + 0. 01) Hz＝25. 01 hz maximum frequency of the next block: fx″ = ( 25 to 0. 01) 赫兹= 24。 99 hz set pattern for digital frequency converter, frequency resolution depends on the performance of the microcomputer system in the whole range of frequency modulation ( Such as 0. 5～400Hz） Is a constant ( For example, & plusmn; 0. 01 hz) 。 Set a pattern for simulation, the resolution of the frequency is associated with the resolution of a given frequency potentiometer, general can achieve the highest output frequency & plusmn; 0. 05%.