Application of automatic switching mode of frequency converter of power station

Abstract

The invention provides application of an automatic switching mode of a frequency converter of a power station. When power-frequency-to-variable-frequency switching of an induced draft fan is carried out during normal running of a unit, in order to be capable of meeting the running characteristics of the unit early, an inlet baffle of the induced draft fan can be manually adjusted by an operator, the furnace pressure is maintained stable, then power-frequency-to-variable-frequency switching of the induced draft fan is carried out, and then the baffle is manually adjusted by the operator to be at the preset opening degree after power-frequency-to-variable-frequency switching is successful. When variable-frequency-to-power-frequency switching of the induced draft fan is carried out, as the inlet baffle of the induced draft fan is basically located at the full-open position, an opening degree curve, corresponding to loads, of the opening degree of the inlet baffle of the induced draft fan needs to be increased to obtain the optimal adjustment mode, and after experiments, it is determined that the inlet baffle of the induced draft fan is limited to be at the opening degree of 60%.

Description

technical field [0001] The invention belongs to the field of applied frequency conversion technology and microelectronics technology, and in particular relates to an application of automatic switching modes of frequency converters in power plants. Background technique [0002] The induced draft fan of unit #2 in Sanmenxia Power Plant is a double-suction centrifugal type, equipped with Beijing Guodian Thinking SWdrive-MV06 / 2500 frequency converter. In January 2013, the frequency converter of unit AB of unit #2 successively caused the unit to stop due to serious faults of the frequency converter; the original quotation Both the power frequency and variable frequency start of the fan are in the knife switch mode, and the power frequency switching and frequency conversion, and the frequency switching power frequency can only be completed by stopping the fan, reducing the load, and turning on the oil. In this context, the operation of the induced draft fan on site urgently needs ...

AI Technical Summary

Problems solved by technology

[0003] In September 2013, during the A-level overhaul of unit #2, the frequency converters of the two induced draft fans of unit #2 in Sanmenxia Power Plant were upgraded. frequency start-up mode, and can realize the frequency conversion switching to power frequency operation mode triggered by the severe fault of the frequency converter, and manual switching between frequency conversion and power frequency. However, during the debugging and trial stage, it was found that the reliability of the frequency converter was poor, the internal circuit was complicated, and the heavy fault signal was frequent. As a result, the frequency converter is frequently switched from the frequency conversion mode to the power frequency mode, which poses a great hidden danger to the adjustment of the negative pressure of the furnace. The furnace negative pressure adjustment idea was formulated due to the poor reliability of the furnace; and the rationality, applicability and correctness of this adjustment idea were further verified through theory, experiments and actual failures during operation.

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