Frequency inverters |
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Frequency inverter for controlling any main equipment could be included to composition of switchgears 6 (10)kV performed according to the technical information KSPE.140.001-13 There is a polyphase input power transformer in a frequency inverter, this is minimize exposure to an electricity network (not more than 5% of the level of generated noise in the network), at that cos φ > 0.96. Usage the cascade circuit of generation of output voltage, based on power IGBT modules and a digital control, this eliminates output filters, because the shape of the output voltage is close to the sine wave, the value of dU/dt is small. That is why frequency inverters are applicable with a system of long output cables without the threat of damage or motor windings insulations. Total efficiency is more than 96,5% (taking into loss in an input transformer and additional devices) and more than 98% for the inverter’s part. The function of automatic regulation of output voltage is realized in frequency inverters, this allows to maintain voltage at a constant level when input voltage fluctuations within ± 10% of U n , thereby providing a stable and safety engine work. Frequency inverters have a high-level security at the expense of next technical decisions:
ПFrequency inverters could be equipped by the function of engine switching from output to input inverter and back (synchronization with the electricity network). Built-in function of diagnostics alarms users to trouble in the power part, the cooling system and need for its services. User-friendly interface makes controlling easier; it is professionally tuned to the requirements of a specific application. Schematic structure of the frequency inverter is shown on the top.
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